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"Gas rumah kaca seperti karbon dioksida merupakan gas yang melimpah di alam sehingga diperlukan cara untuk mengkonversi CO2. Namun, CO2 bersifat stabil secara termodinamika dan kinetika sehingga diperlukan bantuan logam bervalensi rendah contohnya Ni(0) atau Pd(0) untuk dapat bereaksi. Pada penelitian ini digunakan ZSM-5 hirarki terimpregnasi logam nikel sebagai katalis reaksi karboksilasi bertekanan antara fenilasetilena dengan karbon dioksida menjadi asam sinamat. ZSM-5 hirarki dianggap mampu menjadi penyangga katalis logam Ni dikarenakan ZSM-5 hirarki memiliki selektivitas dan transport massa yang baik. ZSM-5 Hirarki disintesis menggunakan metode double template yaitu TPAOH sebagai pengarah struktur MFI dan PDD-AM sebagai pengarah mesopori. Impregnasi logam nikel dilakukan menggunakan metode impregnasi basah dengan reduksi oleh aliran gas hidrogen. Karakterisasi material ZSM-5 hirarki dan Ni/ZSM-5 hirarki dilakukan dengan menggunakan XRD, FTIR, XRF, SEM-EDS dan SAA. Analisa XRD menunjukkan ZSM-5 telah berhasil disintesis. Analisa FTIR menunjukkan dekomposisi template melalui kalsinasi telah berhasil. Pencitraan SEM menunjukkan morfologi material dengan bentuk coffin like-shaped yang merupakan ciri khas ZSM-5. Hasil analisa EDS menunjukkan persen loading Ni dalam ZSM-5 sebesar 1,4 %. Sedangkan analisa XRF menunjukkan persen loading Ni dalam ZSM-5 sebesar 3,325 % yang mengindikasikan logam Ni telah masuk ke dalam pori ZSM-5. Analisa BET menunjukkan adanya hysteresis loop yang mengindikasikan adanya pori berukuran meso. Reaksi karboksilasi bertekanan fenilasetilena dilakukan dalam reaktor batch dengan variasi tekanan CO2 (1, 3, 5, 7 bar) dan suhu (85, 100, dan 125 C). Berdasarkan analisa terhadap campuran produk didapat tekanan CO2 optimum sebesar 3 bar dan suhu optimum pada 85 C.

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Carbon dioxide is one of greenhouse gases which is abundant in nature, therefore efforts are needed to reduce its concentration through CO2 conversion. However, CO2 is thermodynamically and kinetically stable, so it needs low valent metals such as Ni (0) or Pd (0) to help CO2 to react. In this study, the hierarchical ZSM-5 impregnated nickel metal was used as a catalyst for pressurized carboxylation reactions between phenylacetylene and carbon dioxide to cinnamic acid. Hierarchical ZSM-5 is assumed capable for supporting Ni metal catalysts because it has good selectivity and mass transport. Hierarchical ZSM-5 was synthesized using the double template method with TPAOH as structure directing agent for MFI and PDD-AM as mesoporous directing agent. Impregnation of nickel was carried out using a wet impregnation method with reduction by the hydrogen gas flow. Material characterization of hierarchical ZSM-5 and Ni/ZSM-5 was carried out using XRD, FTIR, XRF, SEM-EDS and SAA. XRD analysis shows that ZSM-5 has been successfully synthesized.

FTIR analysis showed that the template decomposition through calcination was successful. SEM imaging of the material shows a coffin-like morphology, which is a characteristic of the ZSM-5. The EDS analysis results shows 1.4% Ni in ZSM-5. While the XRF analysis shows 3.325 % Ni in ZSM-5 of which indicates that Ni has entered the ZSM-5 pores. BET analysis shows a hysteresis loop that indicates mesoporous. Pressurized carboxylation reaction of phenylacetylene were carried out in batch reactors with variations of CO2 pressure (1, 3, 5, 7 bar) and temperature (85, 100, and 125 125 C). Based on the analysis of products with HPLC, the optimal CO2 pressure was obtained at 3 bar and the optimal temperature at 85 C."

"Carbon dioxide is a renewable C1 resource for synthesis chemicals. CO2 in carboxylation reactions requires catalysts Ni complex for CO2 activation. However, the use of Ni complex homogeneous catalysts in the reaction is still less efficient due to the difficult in separating the product and catalyst. Therefore, it is necessary to heterogenize the Ni complex in solid supporting such as mesoporous carbon. In this research, a carboxylation reaction with CO2 was tested using a Ni catalyst that was functionalized with phenanthroline (phen) ligand impregnated on the solid support of mesoporous carbon. Soft template method has been successfully used in mesoporous carbon synthesis with phloroglucinol and formaldehyde prekursors as a carbon source, Pluronic F127 as a structural directing agent, and HCl as an acid catalyst. Modification of the catalyst was carried out by impregnation of Ni from Ni(NO3)2.6H2O which was then functionalized with phenanthroline (phen) ligands into mesoporous carbon to form Ni-phen/MC catalysts. Mesoporous carbon material (MC) and Ni-phen/MC are characterized by FT-IR, XRD, SEM-EDX, and SAA. The results of SAA characterization showed that the pore diameter of MC was 6.7174 nm and Ni-phen/MC was 5.08 nm which indicate that the material was mesoporous. Ni-phen/MC material was then used as a heterogeneous catalyst in the carboxylation reaction of phenylacetylene with CO2. The reaction were carried out in several variations of conditions, temperature variations (25oC, 50oC and 75oC), time variations (4 hours, 8 hours and 16 hours), variations in catalyst types (MC, Ni-phen and Ni-phen/MC). Based on the results of the reaction, the optimum conditions was obtained at 25oC for 8 hour of reaction time using Ni-phen/MC catalyst. The main product of the carboxylation reaction is identified by the HPLC instrument, while the remaining catalyst that has been used in the reaction was identified using the FT-IR instrument.Carbon dioxide is a renewable C1 resource for synthesis chemicals. CO2 in carboxylation reactions requires catalysts Ni complex for CO2 activation. However, the use of Ni complex homogeneous catalysts in the reaction is still less efficient due to the difficult in separating the product and catalyst. Therefore, it is necessary to heterogenize the Ni complex in solid supporting such as mesoporous carbon. In this research, a carboxylation reaction with CO2 was tested using a Ni catalyst that was functionalized with phenanthroline (phen) ligand impregnated on the solid support of mesoporous carbon. Soft template method has been successfully used in mesoporous carbon synthesis with phloroglucinol and formaldehyde prekursors as a carbon source, Pluronic F127 as a structural directing agent, and HCl as an acid catalyst. Modification of the catalyst was carried out by impregnation of Ni from Ni(NO3)2.6H2O which was then functionalized with phenanthroline (phen) ligands into mesoporous carbon to form Ni-phen/MC catalysts. Mesoporous carbon material (MC) and Ni-phen/MC are characterized by FT-IR, XRD, SEM-EDX, and SAA. The results of SAA characterization showed that the pore diameter of MC was 6.7174 nm and Ni-phen/MC was 5.08 nm which indicate that the material was mesoporous. Ni-phen/MC material was then used as a heterogeneous catalyst in the carboxylation reaction of phenylacetylene with CO2. The reaction were carried out in several variations of conditions, temperature variations (25oC, 50oC and 75oC), time variations (4 hours, 8 hours and 16 hours), variations in catalyst types (MC, Ni-phen and Ni-phen/MC). Based on the results of the reaction, the optimum conditions was obtained at 25oC for 8 hour of reaction time using Ni-phen/MC catalyst. The main product of the carboxylation reaction is identified by the HPLC instrument, while the remaining catalyst that has been used in the reaction was identified using the FT-IR instrument."

"ABSTRAKKarbon dioksida (CO2) merupakan senyawa yang potensial digunakan sebagai sumber karbon dalam sintesis fine chemicals karena keberadaannya melimpah di alam, bersifat non toksik, ekonomis, dan termasuk ke dalam sumber yang dapat diperbaharui. Namun pemanfaatan CO2 secara luas masih terkendala karena sifatnya yang inert dan stabil. Oleh karena itu, keberadaan katalis sangat diperlukan dalam proses konversi CO2. Penelitian ini bertujuan untuk mensintesis Cu terimpregnasi pada karbon mesopori sebagai katalis karboksilasi fenilasetilena dengan CO2 menjadi asam karboksilat. Pembuatan karbon mesopori dilakukan dengan metode soft template menggunakan Pluronik F-127 sebagai pembentuk pori, formaldehida dan floroglusinol sebagai sumber karbon, dan HCl sebagai katalis asam. Material Cu/MC yang dihasilkan dikarakterisasi dengan FTIR, XRD, SAA, dan SEM-EDX. Analisis BET terhadap karbon mesopori menunjukkan bahwa material tersebut memiliki luas permukaan sebesar 405,8 m2/g dengan rata-rata pori sebesar 7,2 nm. Hasil analisa dengan XRD memperlihatkan puncak pada 2θ 36,62°; 43,47°; 50,63°; dan 74,19° yang mengindikasikan bahwa Cu telah berhasil terimpregnasi yang mewakili spesi Cu(0) dan Cu(I). Reaksi karboksilasi fenilasetilena dengan CO2 dilakukan dengan variasi suhu (25°C; 50°C; dan 75°C), variasi jumlah katalis (28,6; 57,2; dan 85,8 mg) dan variasi basa (Cs2CO3; K2CO3; dan Na2CO3). Hasil reaksi dianalisa dengan HPLC dan memperlihatkan %konversi terbaik terjadi pada suhu 75°C yaitu 41,32% dengan menggunakan Cs2CO3 sebagai basa, dan produk yang terbentuk diidentifikasi dengan FTIR dan LC-MS.

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ABSTRACTCarbon dioxide (CO2) is a compound that has the potential to be used as carbon source in the synthesis of fine chemicals because it is abundant in nature, non-toxic, inexpensive, and is included as a renewable source. However, utilization of CO2 is stillconstrained due to its inert and stable nature. Therefore, the presence of a catalyst is needed in CO2 conversion. This study aims to synthesize impregnated Cu on mesoporous carbon (Cu/MC) as a catalyst for phenylacetylene carboxylation reaction with CO2 into carboxylic acid. The synthesis of mesoporous carbon was performed via soft template method using Pluronic F-127 as a pore forming agen, formaldehyde and phloroglucinol as carbon sources, and HCl as an acid catalyst. The Cu/MC material produced was characterized by FTIR, SAA, XRD, and SEM-EDX. BET surface area analysis of mesoporous carbon showed that the material has a surface area of 405.8 m2/g with an average pore diameter of 7,2 nm. XRD pattern of Cu/MC showed some sharp peaks at 2θ of 36.62°; 43.47°; 50.63°; and 74.19° which indicates that Cu has been successfully impregnated in the form of Cu(0) and Cu(I). Phenylacetylene carboxylation reaction with CO2 was carried out by varying reaction temperatures (25, 50, and 75 °C), the amount of catalyst (28.6, 57.2, and 85.8 mg) and the type of base (Cs2CO3, K2CO3, and Na2CO3). The reaction mixtures were analyzed by HPLC and showed that highest phenylacetylene conversion of 41% was obtained for the reaction at 75°C using Cs2CO3 as a base. The product was further identified using FTIR and LCMS."

"Karbondioksida merupakan gas rumah kaca yang menjadi salah satu faktor pemanasan global dan perubahan iklim secara drastis. Namun, di samping dampak negatif emisi gas CO2 secara alami maupun melalui hasil kegiatan antropogenik, CO2 dapat dimanfaatkan sebagai sumber C1 reaksi organik, salah satunya reaksi karboksilasi. Periodic Mesoporous Organosilica (PMO) merupakan material mesopori silika yang memiliki keunggulan, di antaranya memiliki ukuran pori cukup besar yang dapat memfasilitasi transfer massa dengan baik, luas permukaan besar yang memungkinkan banyak sisi katalitik, maupun integrasi dari spesi organik dan atom logam dalam kerangka PMO. Logam nikel merupakan logam yang secara luas digunakan dalam bidang katalisis, karena logam tersebut memiliki orbital d tidak terisi penuh, sehingga dapat membentuk ikatan kovalen koordinasi dan memudahkan proses pembentukan intermediet pada permukaan katalis. Pada penelitian ini, dilakukan sintesis PMO dengan prekursor 4,4’- bis(trietoksisilil)bifenil dan dilanjutkan dengan fungsionalisasi gugus amina melalui proses nitrasi dan aminasi. Selanjutnya, dilakukan imobilisasi kompleks Ni(acac)2 pada material Bph-PMO untuk digunakan sebagai katalis pada reaksi karboksilasi fenilasetilena dengan CO2. Analisis XRD menunjukkan bahwa fungsionalisasi gugus amina pada Bph-PMO tidak merubah komponen maupun struktur periodik pada Bph-PMO, begitu pula setelah nikel diimobilisasi pada Bph- PMO yang terfungsionalisasi gugus amina. Analisis FTIR Ni/NH2-Bph-PMO menunjukkan puncak serapan pada 1605 cm-1 yang mengindikasikan pembentukan ikatan C=N dari reaksi kondensasi Schiff antara gugus amina dengan C=O pada Ni(acac)2. Material Ni/NH2-Bph-PMO memiliki ukuran partikel rata-rata 420 nm, dengan pemuatan nikel 2,8% berdasarkan analisis SEM-EDX. Analisis TEM menunjukkan keberadaan struktur mesopori pada NH2-Bph-PMO. Ukuran diameter pori dan luas permukaan BET material Ni/NH2-Bph-PMO berturut-turut sebesar 3,16578 nm dan 490,742 m2/g. Uji katalitik material Ni/NH2-Bph-PMO pada karboksilasi fenilasetilena dengan CO2 dilakukan pada tiga variasi suhu, di mana kondisi optimum diperoleh pada suhu 25 °C, dengan konsentrasi produk fenil maleat 244,5899 ppm.

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ABSTRACTCarbon dioxide is a greenhouse gas that affecting global warming and produces climate change. However, aside from the negative effects of natural CO2 gas emissions and through anthropogenic activities, CO2 has been used as a source of C1 organic reactions, for example, carboxylation reaction. Periodic Mesoporous Organosilica (PMO) is a superior silica mesoporous material, which has a large pore to facilitate mass transfer, a large area that allows many catalytic sides, which also associated with organic species and metal atoms in PMO. This property supports PMO to be applied as a metal catalyst support. Nickel metal is a metal that is widely used in the catalysis field, because this metal has d orbitals and is not fully filled, so it can form covalent bonds and fasilitate process of making intermediates on the surface of the catalyst. In this study, PMO was synthesized with 4,4'-bis (triethoxysilyl) biphenyl precursor and continued with the functionalization of amine groups through nitration and amination process. Furthermore, immobilization of Ni(acac)2 complex was carried out on the Bph-PMO material to be used as a catalyst in the carboxylation reaction of phenylacetylene with CO2. Analysis of XRD shows that the functionalization of amine groups on Bph-PMO does not change the periodic structure of Bph-PMO, as well as after nickel immobilized on aminated Bph-PMO. Absorption peak at 1605 cm-1 of Ni/NH2- Bph-PMO revealed from FTIR analysis, indicating new C=N bond from Schiff condensation between amine group and C=O from Ni(acac)2. Ni/NH2-Bph-PMO material has an average particle size of 420 nm, with 2,8% nickel loading based on SEM-EDX analysis. Mesoporous structure of NH2-Bph-PMO has been proved by TEM analysis. The pore diameter size and BET surface area of Ni/NH2-Bph-PMO are 3,16578 nm and 490,742 m2/g, respectively. The catalytic test of Ni/NH2-Bph- PMO on phenylacetylene carboxylation with CO2 was carried out at three temperature variations, which shows that optimum condition was obtained at 25 °C, with a concentration of phenyl maleic product of 244,5899 ppm."

"Karbon dioksida merupakan salah satu gas utama yang menyebabkan emisi gas rumah kaca yang berada pada atmosfer. Dikarenakan sifatnya yang inert, CO2 sulit bereaksi dengan senyawa lain sehingga dibutuhkan suatu katalis. Pada penelitian ini digunakan zeolit ZSM-5 berpori hirarki bersumber mineral alam yaitu zeolit alam Bayat dan kaolin Bangka yang diimpregnasi bimetal NiZn sebagai katalis untuk mengkonversi CO2 dengan bantuan dari asetilena untuk menghasilkan asam akrilat. Zeolit ZSM-5 alam berpori hirarki disintesis menggunakan metode double template, dengan primary template TPAOH sebagai pengarah framework MFI serta secondary template PDDA-M sebagai pengarah struktur mesopori. Impregnasi logam bimetal nikel (Ni) dan seng (Zn) dengan metode co-impregnation lalu direduksi dengan aliran gas H2. Karakterisasi material ZSM-5 alam berpori hirarki dan NiZn/ZSM-5 alam berpori hirarki dilakukan dengan menggunakan FTIR, XRD, XRF, dan SEM-EDS. Analisis XRD menunjukkan kristalinitas dari ZSM-5 alam berpori hirarki berhasil disintesis. Analisis FTIR menunjukkan telah terjadinya dekomposisi template melalui kalsinasi. Pencitraan SEM menunjukkan morfologi material dengan bentuk coffin like-shaped yang merupakan ciri khas ZSM-5. Hasil analisisis EDS menunjukkan persen loading Ni dan Zn dalam ZSM-5 masing-masing sebesar 6,38% dan 3,23%. Reaksi karboksilasi asetilena dengan CO2 dilakukan dalam reaktor batch dengan variasi tekanan yaitu 1,5 bar, 2,5 bar, dan 3,5 bar. Produk hasil reaksi yang terbentuk dianalisis dengan HPLC. Dari hasil analisis HPLC diperoleh puncak pada waktu retensi 3,45 menit dengan kondisi optimum yaitu tekanan 2,5 bar, dan luas area sebesar 302,836 mAU. Sehingga, menunjukkan tidak adanya asam akrilat dalam produk.

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Carbon dioxide is one of the main gases that cause greenhouse gas emissions in the atmosphere. Because of its inert in the atmosphere, the catalyst is needed to help CO2 react with other compounds. In this research, hierarchical ZSM-5 was prepared from natural minerals as sources, which is natural zeolite Bayat and Bangka kaolin then impregnated with bimetallic Ni-Zn as a catalyst to convert CO2 with support of acetylene to produce acrylic acid. Hierarchical zeolite ZSM-5 was synthesized using double template method, with TPAOH as its primary template that directed to MFI framework and PDDA-M as its secondary template that directed mesoporous structure. Impregnation of nickel (Ni) and zinc (Zn) bimetallic was conducted by co-impregnation method followed by reduction H2 gas flow. Material characterization of natural ZSM-5 hierarchy and NiZn/ZSM-5 hierarchy were conducted FTIR, XRD, XRF, and SEM-EDS. FTIR analysis shows that there has been a decomposition of templates through calcination. XRD analysis showed that the crystallinity of the ZSM-5 hierarchy was synthesized successfully. SEM analysis shows the morphology of the material with the coffin like-shaped which is characteristic of the ZSM-5. The EDS analysis shows percent loading of Ni and Zn in ZSM-5 are 6.38% and 3.23%. The acetylene carboxylation reaction with CO2 was carried out in a batch reactor with pressure variations 1.5 bar, 2.5 bar, and 3.5 bar. The products formed were analyzed by HPLC and GCMS. HPLC analysis shows a new peak at a retention time of 3,625 minutes. The optimum condition was obtained at 2.5 bar and the value is 302.836 mAU. So, it shows do not contain acrylic acid in the product."

"Konversi karbon dioksida CO2 menjadi senyawa lain menjadi sangat menguntungkan karena jumlahnya di atmosfer yang melimpah, namun karbon dioksida CO2 memiliki termodinamik dan kinetik yang stabil sehingga diperlukan bantuan logam bervalensi rendah contohnya Ni 0 untuk dapat bereaksi. Pada penelitian ini digunakan ZSM-5 terimpregnasi logam nikel sebagai katalis reaksi karboksilasi asetilena dengan karbon dioksida menjadi asam akrilat. Hasil karakterisasi XRD menunjukan bahwa material ZSM-5 memiliki kristalinitas yang tinggi berhasil disintesis. Analisa menggunakan SEM menunjukan bahwa ZSM-5 memiliki morfologi bentuk coffin-like dan setelah diimpregnasi tidak mempengaruhi struktur morfologi kristal. Karakterisasi menggunakan BET ZSM-5 hirarki yang disintesis memiliki pori berukuran meso karena terbentuk hystheresis loop. Analisa menggunakan AAS menghasilkan loading logam nikel pada ZSM-5 mikropori sebesar 1,9 sedangkan ZSM-5 hirarki sebesar 2,1. Karakterisasi XPS menunjukan logam nikel pada ZSM-5 memiliki biloks nol 0. Pada reaksi karboksilasi asetilena dengan karbon dioksida dengan target produk asam akrilat, analisis HPLC tidak menunjukan adanya asam akrilat dalam reaksi. Namun, terdapat puncak lain pada waktu retensi 3,625 dimana pada material ZSM-5 hirarki didapatkan kondisi optimum pada suhu 80oC dengan suhu 12 jam dan menggunakan katalis Ni 0 /ZSM-5 mikropori didapatkan kondisi optimum pada suhu 40oC dan waktu 12 jam.

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Conversion of carbon dioxide CO2 into other compounds become very advantageous because of the abundance in the atmosphere, but carbon dioxide CO2 has thermodynamic and kinetic stable so it need low valent metal for example Ni 0 to react. In this studym ZSM 5 impregnated with nickel metal as catalyst of carboxylation reaction of acetylene with carbon dioxide to acrylic acid. XRD characterization results ZSM 5 material has high crytalinity successfully synthesized. Analysis using SEM obtain ZSM 5 has coffin like morphology and after impregnation doesnt affect the crystal morphology structure. Characterization using BET proves that ZSM 5 hierarchy has meso sized pore because of the hysthereses loop. Analyzing using AAS obtained that load of nickel metal on ZSM 5 micropore equal to 1,9 meanwhile ZSM 5 hierarchy equal to 2,1. The characterization of XPS show nickel metal on ZSM 5 has zero 0 oxidation. Carboxylation reaction of acetylene with carbon dioxide targeted acrylic acid product, HPLC analysis doesnt show the presence of acrylic acid in the reaction. However, there was another peak at retention time of 3,625 where in herarchical ZSM 5 material the optimum condition was obtained at temperature 80oC with 12 hours while using Ni 0 ZSM 5 micropore catalyst obtained 80oC with 12 hours. "

"ABSTRAKGrafena adalah alotrop karbon yang kristalnya tersusun secara heksagonal dengan hibridisasi sp2. Grafena dan nanokompositnya dengan berbagai logam transisi telah dikembangkan untuk berbagai aplikasi, mulai dari sensor, elektronik, energi hingga bidang biomedis. Selain itu, nanokomposit berbasis graphene juga banyak dikembangkan untuk aplikasinya sebagai katalis karena memiliki luas permukaan yang besar serta memiliki konduktivitas dan stabilitas yang baik. Pada penelitian ini, graphene oxide (rGO) tereduksi yang dimodifikasi dengan nanopartikel Ag disintesis sebagai katalis heterogen dalam reaksi karboksilasi antara fenilacetylene dan CO2. Karakterisasi nanokomposit AgNPs / graphene oxide tereduksi dilakukan dengan menggunakan Scanning Electron Microscopy - Spektroskopi sinar-X dispersif energi, Fourier Transform Infra Red, X-ray Powder Diffraction dan UV-Vis Spectroscopy. Berdasarkan hasil UV-Vis didapatkan puncak absorbansi pada panjang gelombang 253 nm yang menunjukkan adanya restorasi konjugasi elektronik pada permukaan rGO. Spektrum FTIR dari nanokomposit AgNPs / rGO menunjukkan penurunan intensitas absorbansi gugus hidroksil dan keton dibandingkan dengan spektrum oksida graphene, menunjukkan bahwa reduksi gugus fungsi yang mengandung oksigen telah berhasil dilakukan dengan menggunakan urea. Hasil XRD menunjukkan intensitas puncak pada 38.14o (111), 44.27o (200), 64.43o (220), 77.38o (311), menunjukkan bahwa nanopartikel Ag yang terbentuk memiliki kristalografi fcc. Hasil SEM-EDX menunjukkan nanopartikel Ag tersebar di permukaan rGO dengan persentase massa 38,57%. Reaksi karboksilasi dilakukan dalam reaktor batch dengan variasi basa dan suhu. Berdasarkan hasil analisis produk menggunakan HPLC, luas produk utama terbesar yang diperoleh dari reaksi menggunakan basa Na2CO3 adalah 204,1361 dan suhu 50oC adalah 128,2214. Sedangkan luas produk minor terbesar diperoleh dari reaksi menggunakan basa Cs2CO3 sebesar 6,2175 dan suhu 80 oC sebesar 18,3130.ABSTRACTGraphene is an allotrope of carbon whose crystals are arranged hexagonally by sp2 hybridization. Graphene and its nanocomposites with various transition metals have been developed for a wide range of applications, from sensors, electronics, energy to biomedical fields. In addition, graphene-based nanocomposites have also been widely developed for applications as catalysts because they have a large surface area and have good conductivity and stability. In this study, reduced graphene oxide (rGO) modified with Ag nanoparticles was synthesized as a heterogeneous catalyst in the carboxylation reaction between phenylacetylene and CO2. Characterization of reduced AgNPs / graphene oxide nanocomposites was performed using Scanning Electron Microscopy - Energy dispersive X-ray spectroscopy, Fourier Transform Infra Red, X-ray Powder Diffraction and UV-Vis Spectroscopy. Based on the UV-Vis results, the absorbance peak was obtained at a wavelength of 253 nm which indicated the presence of electronic conjugation restoration on the rGO surface. The FTIR spectrum of the AgNPs/rGO nanocomposite showed a decrease in the absorbance intensity of the hydroxyl and ketone groups compared to the graphene oxide spectrum, indicating that the reduction of oxygen-containing functional groups was successfully carried out using urea. XRD results showed peak intensities at 38.14o (111), 44.27o (200), 64.43o (220), 77.38o (311), indicating that the Ag nanoparticles formed had fcc crystallography. The SEM-EDX results showed that Ag nanoparticles were scattered on the surface of rGO with a mass percentage of 38.57%. The carboxylation reaction was carried out in a batch reactor with variations in base and temperature. Based on the results of product analysis using HPLC, the largest area of ​​the main product obtained from the reaction using the base Na2CO3 was 204.1361 and a temperature of 50oC was 128.2214. Meanwhile, the largest minor product area was obtained from the reaction using the base Cs2CO3 of 6.2175 and a temperature of 80 oC of 18.3130."

"Pemanfaatan bahan bakar fosil, batu bara, minyak, serta gas alam yang kaya akan karbon semakin marak digunakan guna keberlangsungan hidup manusia. Pemanfaatan bahan-bahan tersebut juga turut andil dalam peningkatan konsentrasi CO₂ di atmosfir. Meningkatnya emisi CO₂ menyebabkan turut meningkatnya suhu bumi dan perubahan iklim yang disebabkan oleh ‘efek rumah kaca’. Sehingga, konversi CO₂ menjadi senyawa yang lebih bermanfaat sangatlah diperlukan. Dalam penelitian ini, dilakukan sintesis dan karakterisasi karbon mesopori termodifikasi NiZn sebagai katalis heterogen reaksi karboksilasi asetilena dengan CO₂. Karbon mesopori disintesis dengan metode soft template menggunakan surfaktan pluronik F127 sebagai template organik, serta phloroglucinol sebagai prekursor karbon. Karbon mesopori kemudian dimodifikasi dengan logam nikel dan seng (NiZn/MC) dengan metode deposisi-presipitasi homogen, dilanjutkan dengan reduksi dengan aliran gas H₂ (30 ml per menit) selama 90 menit pada suhu 400 ^oC. Pola difraksi XRD menunjukkan puncak-puncak pada 2q sekitar 31,79^o; 34,54^o; 36,31^o; 44,04^o; 51,51^o; 56,51^o; 62,22^o; dan 75,68^o yang mengindikasikan terdapatnya spesi NiZn dan ZnO. Berdasarkan hasil EDX, material karbon mesopori berhasil dimodifikasi dengan logam nikel dan seng dengan persen loading 11,68%, untuk nikel dan 8,69% untuk logam seng. Katalis NiZn/MC kemudian digunakan sebagai katalis heterogen dalam reaksi karboksilasi asetilena dengan CO₂. Reaksi dilakukan dalam reaktor batch dengan kondisi reaksi yang bervariasi, yakni tekanan 1,5 bar; 2,5 bar; dan 3,5 bar. Asam akrilat, sebagai produk yang diinginkan, tidak terdeteksi pada analisis dengan HPLC. Namun, terdeteksi spesi yang lebih polar pada waktu retensi 3 menit, di mana kondisi optimum terjadi pada tekanan 2,5 bar.

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Utilization of fossil fuel, charcoal, oil, and natural gases, which are carbon-rich materials, is widely used for human sustainability. However, utilization of such materials contributes to higher atmospheric CO₂ concentration. The increase of CO₂ emission leads to higher temperature and climate change ea t ‘green house effect’. Therefore, conversion of CO₂ to value-added chemicals has drawn many attentions. In this research, carboxylation reaction of acetylene and CO₂ has been carried out using mesoporous carbon modified by nickel and zinc metals as heterogeneous catalyst. Mesoporous carbon has been successfully synthesized using soft template method with pluronic F127 as template and phloroglucinol as carbon precursor. Mesoporous carbon was then modified with nickel and zinc (NiZn/MC) using homogeneous deposition precipitation method, followed by reduction for 90 mins at 400 ^oC under a flow of H₂ (30 ml/min). XRD diffraction pattern showed peaks for 2q around 31.79^o, 34.54^o, 36.31^o, 44.04^o, 51.51^o, 56.51^o, 62.22^o, and 75.68^o which indicate the presence of NiZn and ZnO. EDX result revealed that mesoporous carbon material has been successfully modified by nickel and zinc metals, with 11.68% and 8.69% metal loadings for nickel and zinc, respectively. NiZn/MC catalyst was then used for carboxylation reaction of acetylene with CO₂. The reactions were carried out in batch reactor with varied pressure, 1.5 bar, 2.5 bar, and 3.5 bar. Acrylic acid, as the desired product, was not observed in analysis with HPLC. However, more polar species was noticed at retention time of 3 minutes, where optimum pressure was found to ea t 2.5 bar."

"Sintesis karbon mesopori secara soft template dan hard template dari berbagai prekursor karbon; phloroglucinol, glukosa, dan hidrolisat tandan kosong kelapa sawit (TKKS) telah dilakukan. Pluronic F127 dan silica gel digunakan sebagai cetakan pada sintesis karbon mesopori soft template dan hard template, secara berturut-turut. Material karbon mesopori kemudian diimpregnasi dengan logam Ni dan direduksi menggunakan gas H2 sehingga membentuk Ni/mesoporous carbon (Ni/MC). Karakterisasi material dengan FTIR menunjukkan bahwa gugus organik pada soft templated mesoporous carbon (ST MC) menghilang setelah proses karbonisasi dan pada hard templated mesoporous carbon (HT MC) setelah proses desilikasi, mengindikasikan bahwa proses tersebut efektif dalam penghilangan template yang digunakan. Berdasarkan analisis SEM, material karbon memiliki morfologi seperti serpihan dengan tambahan sebaran butiran halus setelah impregnasi. Berdasarkan hasil analisis XRD untuk ST MC dan HT MC, terdapat difraksi khas karbon grafit pada 2θ 25⁰ dan 44⁰. Kemudian terdapat tambahan difraksi setelah impregnasi pada 2θ 45⁰ dan 52⁰ yang bersesuaian dengan Ni(0), mengindikasikan bahwa impregnasi berhasil dilakukan. Analisa luas permukaan menunjukkan bahwa material karbon memiliki luas permukaan dan distribusi pori yang bervariasi. Material selanjutnya digunakan sebagai katalis dalam reaksi karboksilasi fenilasetilena dengan karbon dioksida. Analsis HPLC menunjukkan hasil terbaik pada suhu reaksi 85⁰C dan waktu reaksi 8 jam dengan menggunakan katalis HT Ni/MC phloroglucinol dan garam MgCl2. Yield pembentukan produk asam fenil propiolat pada kondisi tersebut adalah 2,2 %.

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Synthesis of soft templated and hard templated mesoporous carbon from various carbon precursors; phloroglucinol, glucose, and empty palm oil shell hidrolisate, has been conducted successfully. Pluronic F127 and silica gel were used as template in the sythesis of soft and hard templated mesoporous carbon, respectively. The materials were then impregnated with Ni and reduced under H2 flow to form Ni/Mesoporous Carbon (Ni/MC). Characterization with FTIR shows that the organic groups in Soft Templated Mesoporous Carbon (ST MC) disappear after the carbonization process and in Hard Templated Mesoporous Carbon (HT MC) after the desilication process, indicating that the process is effective in template removal. Based on the SEM analysis, carbon materials have flakes-like morphology with the addition of fine grain spreads after impregnation. Based on the results of XRD analysis for ST MC and HT MC, there are a typical graphite carbon diffractions on 2θ of 25 and 44 ⁰. There are also additional diffraction peaks at 2θ of 45 and 52⁰ after impregnation which correspond with Ni(0), indicating that the Ni impregnation was successfully performed. The analysis of the surface area indicates that carbon materials have various surface area and pore distribution. The materials are subsequently used as a catalyst in the carboxylation reaction of phenylacetylene with carbon dioxide. HPLC analysis shows the best resultis obtained at reaction temperature of 85 ⁰ _C and time of 8 hour using MgCl2 salt and HT Ni/MC phloroglucinol catalyst. Yield of phenyl propiolic acid formation as product of carboxylation obtained on optimum condition is 2,2%."

"CO2 merupakan gas yang inert, tidak beracun, tidak mudah terbakar, dan menjadi gas penyumbang terbesar dalam efek rumah kaca yang menyebabkan suhu permukaan bumi naik. Di sisi lain, kelimpahannya yang tinggi di alam menjadikan CO2 sebagai sumber karbon yang potensial dalam sintesis fine chemicals. Dalam penelitian ini dilakukan studi reaksi karboksilasi fenilasetilena dengan CO2 menggunakan katalis logam Ni terimpregnasi pada support karbon mesopori. Karbon mesopori telah berhasil disintesis dengan metode soft template menggunakan Pluronik F127 sebagai pembentuk pori, formaldehida dan phloroglucinol sebagai sumber karbon, dan HCl sebagai katalis asam. Material ini dikarakterisasi dengan FTIR, XRD, SEM, dan BET. Spektra FTIR dari karbon mesopori sebelum karbonisasi memiliki puncak serapan 3500 2800 cm-1 yang menunjukkan adanya stretching C-H dan stretcing O-H dari phloroglucinol dan formaldehida. Sedangkan setelah karbon mesopori dikarbonisasi, puncak serapan pada bilangan gelombang tersebut hilang. Karakterisasi dengan XRD menunjukkan adanya dua puncak pada 2 yakni 24,26o dan 42,76o yang menandakan puncak khas dari karbon mesopori. Analisis luas permukaan dengan BET menghasilkan isoterm adsorpsi N2 pada karbon mesopori yang menunjukkan adanya hystersis loop pada rentang P/Po sekitar 0,4-0,9 yang merupakan karakter dari karbon mesopori. Karbon mesopori hasil sintesis memiliki distribusi ukuran pori sebesar 7.2 nm yang termasuk dalam rentang material mesopori 2-50 nm . Karakterisasi dengan SEM menunjukkan bentuk yang datar dengan ukuran kristal beragam. Modifikasi support dilakukan dengan cara impregnasi logam Ni ke dalam karbon mesopori Ni@MC . Katalis Ni@MC digunakan sebagai katalis dalam reaksi karboksilasi fenilasetilena dengan CO2. Reaksi dilakukan dalam reaktor batch dengan kondisi reaksi yang bervariasi, yakni suhu 25oC, 50oC, 85oC dan waktu 8 jam, 12 jam, dan 16 jam. Hasil analisis campuran produk dengan HPLC menunjukkan terbentuknya asam sinamat sebesar 1,52 pada sampel 85oC 8jam, 2,83 pada sampel 85oC 12jam, dan 0,62 pada sampel 85oC 16jam.

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CO2 is an inert, non toxic, non flammable, and the largest contributor gas to greenhouse gases causing the earth 39 s surface temperature to rise. Its high abundance in nature makes CO2 a potential carbon source in fine chemical synthesis. In this research, carboxylation reaction of phenylacetylene with CO2 has been studied using an impregnated nickel catalyst on mesoporous carbon support. Mesoporous carbon has been successfully synthesized by soft template method using Pluronic F127 as pore forming, formaldehyde and phloroglucinol as carbon source, and HCl as acid catalyst. This material was characterized by FTIR, XRD, SEM, and BET analysis. The FTIR spectra of the mesoporous carbon before carbonization had an absorption peak of 3500 2800 cm 1 indicating the presence of stretching C H and stretching O H of phloroglucinol and formaldehyde. Meanwhile after carbonization, those peaks disappear. Characterization with XRD shows the presence of two peaks at 2 24.26 and 42.76 which denotes the typical peak of mesoporous carbon. BET Surface Area Analysis gave N2 adsorption isotherm on mesoporous carbon indicating a hysterysis loop in the P Po range 0.4 0.9 which is a character of mesoporous carbon. Synthesized mesoporous carbon had pore size distribution of 7.2 nm which is included in the mesoporous material range 2 50 nm . Characterization with SEM shows a flat shape with varying crystal sizes. Modification of support has been conducted by impregnation of Ni metal into mesoporous carbon Ni MC . The Ni MC catalyst was used as a catalyst in the carboxylation reaction of phenylacetylene with CO2. The reactions were carried out in a batch reactor under various reaction conditions at reaction temperature of 25oC, 50oC, and 85oC and for over 8, 12, and 16 hours. HPLC analysis of the product mixtures shows that cinnamic acid was formed with 1,52 yield in 85oC 8h sample, 2,83 yield in 85oC 12h sample, and 0,62 yield in 85oC 16h sample."