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Synthesis and Characterization of Mesoporous Carbon Supported Ni-Ga Catalyst for Low-Pressure CO2 Hydrogenation Uwin Sofyani; Yuni Krisyuningsih Krisnandi; Iman Abdullah
Bulletin of Chemical Reaction Engineering & Catalysis 2022: BCREC Volume 17 Issue 2 Year 2022 (June 2022)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17.2.13377.278-285

In this study, the atmospheric-pressure hydrogenation of CO2 was carried over bimetallic Ni-Ga catalyst supported on mesoporous carbon (MC). MC was successfully prepared using the soft-template method as proven by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy - Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Brunauer–Emmett–Teller Surface Area Analyzer (BET SAA), and Transmission Electron Microscopy (TEM) characterizations. The Ni-Ga/MC catalyst was synthesized using the impregnation method, and based on the XRD characterization, the formation of bimetallic Ni-Ga on the MC support is confirmed. The EDS mapping image shows the uniform distribution of the bimetallic Ni-Ga on the MC surface, especially for the Ni5Ga3/MC and NiGa3/MC catalysts. Moreover, the TEM images show an excellent pore size distribution. The formation of Ni-Ga alloy was identified as an active site in the CO2 hydrogenation. Ni5Ga3/MC catalyst exhibited a 10.80% conversion of CO2 with 588 μmol/g formaldehyde at 1 atm, 200 °C, and H2/CO2 ratio of 3/1. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis and Characterization of Copper Impregnated Mesoporous Carbon as Heterogeneous Catalyst for Phenylacetylene Carboxylation with Carbon Dioxide Putri Nurul Amalia; Iman Abdullah; Dyah Utami Cahyaning Rahayu; Yuni Krisyuningsih Krisnandi
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.52778

Carbon dioxide (CO2) is a compound that can potentially be used as a carbon source in the synthesis of fine chemicals. However, the utilization of CO2 is still constrained due to its inert and stable nature. Therefore, the presence of a catalyst is needed in CO2 conversion. This study aims to synthesize copper impregnated mesoporous carbon (Cu/MC) as a catalyst for phenylacetylene carboxylation reaction with CO2 to produce phenylpropiolic acid. The synthesis of mesoporous carbon was performed via the soft template method. The as-synthesized Cu/MC material was characterized by FTIR, SAA, XRD, and SEM-EDX. BET surface area analysis of mesoporous carbon showed that the material has a high surface area of 405.8 m2/g with an average pore diameter of 7.2 nm. XRD pattern of Cu/MC 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), amount of catalyst (28.6, 57.2, and 85.8 mg), type of base (Cs2CO3, K2CO3, and Na2CO3), and variation of support. The reaction mixtures were analyzed by HPLC and showed that the highest phenylacetylene conversion of 41% was obtained for the reaction at 75 °C using Cs2CO3 as a base.

Modifikasi Lapisan Difusi dengan Pengikat Silang N,N’Metilenbisakrilamida (MBA) pada Sistem DGT Berbasis Gel dengan Adsorben TiO2 untuk Penentuan Konsentrasi Fosfat di Lingkungan Akuatik Asep Saefumillah; Dhania Dwi Aprianti; Iman Abdullah; Inna Husna
Sainsmat : Jurnal Ilmiah Ilmu Pengetahuan Alam Vol 2, No 2 (2013): September
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Negeri Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35580/sainsmat228562013

Konsentrasi fosfat yang tinggi di lingkungan akuatik dapat menyebabkan terjadinya ledakan alga yang dapat mengakibatkan ketidakseimbangan ekosistem air. Oleh karena itu, penentuan ketersediaanbiologi (bioavailabilitas) fosfat perlu dilakukan untuk mengetahui konsentrasinya dalam air. Salah satu metode efektif yang saat ini digunakan dalam penentuan bioavailabilitas fosfat di lingkungan akuatik adalah menggunakan perangkat Diffusive Gradient in Thin Films (DGT) dengan gel berpengikat TiO2. Pada penelitian ini dilakukan modifikasi pengikat silang pada gel poliakrilamida yang digunakan sebagai diffusive gel pada sistem DGT untuk meningkatkan selektivitasnya terhadap anion ortofosfat. Pengikat silang yang digunakan untuk modifikasi adalah N,N’-Metilenbisakrilamida (MBA). Pengaruh variasi konsentrasi pengikat silang MBA terhadap koefisien difusi menghasilkan nilai koefisien difusi berbanding terbalik dengan konsentrasi pengikat silangnya. Pembandingan selektivitas diffusive gel DGT dengan pengikat silang MBA dilakukan melalui perhitungan kadar fosfat total pada kedua sistem tersebut dengan adanya anion pengganggu berupa asam fitat dan asam humat. Perhitungan dilakukan menggunakan sistem deployment dalam waktu 24 jam dan variasi konsentrasi pengikat silang MBA (0,05%; 0,2%; dan 0,3%). Melalui perhitungan ini diketahui bahwa gel pendifusi (diffusive gel) dengan konsentrasi pengikat silang MBA sebesar 0,3% menunjukkan selektivitas terbaik terhadap anion ortofosfat. Hal ini dibuktikan melalui percobaan dengan suatu gangguan fosfat organik. Konsentrasi asam fitat dan asam humat yang teradsorpsi pada sistem ini cenderung tetap meski konsentrasinya bertambah. Hal ini membuktikan bahwa diffusive gel MBA 0,3% memiliki batas tertentu dalam melewatkan kedua asam organik tersebut, yaitu hanya sebesar 28,753 μg untuk asam fitat dan untuk asam humat sebesar 33,177 μg. Berdasarkan penelitian ini dapat disimpulkan bahwa MBA dapat digunakan sebagai pengikat silang pada diffusive gel poliakrilamida dalam sistem DGT. Penggunaan pengikat silang MBA juga dapat menghasilkan pengukuran kadar ketersediaan biologi fosfat yang lebih akurat karena lebih selektif terhadap ortofosfat dan bersifat membatasi jumlah fosfat organik yang terdifusi yang dapat mengganggu analisis kadar ortofosfat.Kata Kunci: DGT, Ortofosfat, (MBA), Koefisien Difusi, Gel Pendifusi

The Use of Silica Extracted from Kaolin as Catalyst Support for Esterification of 4-Hydroxybenzoic Acid with Sucrose Iman Abdullah; Widayanti Wibowo; Soleh Kosela; Yuni Krisyuningsih Krisnandi
Jurnal Kimia Sains dan Aplikasi Vol 23, No 6 (2020): Volume 23 Issue 6 Year 2020
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

SiO2 was extracted from kaolin using concentrated HCl and HNO3 mixture and used as solid support for both Bronsted (HClO4 and H2SO4) and Lewis Acid (AlCl3 and ZnCl2). Before extraction, kaolin was calcined at 800°C for eight hours to form metastable kaolin. After the extraction procedure, silica was recovered in 51.6% yield. Silica and the resulting solid acids were then characterized using XRD, XRF, and FTIR. XRD pattern shows that silica synthesized from kaolin is in the mixture of amorphous and α-quartz silica. Immobilization of acids alters its structure becomes more crystalline. XRF analysis shows that the loading of AlCl3 and ZnCl2 was 9.5 and 24.8%, respectively. The acid catalysts were then used in the esterification reaction of 4-hydroxybenzoic acid with sucrose. The reactions were conducted in dimethyl sulfoxide (DMSO) solvent by varying reaction time and reaction temperature. The highest conversion of starting materials and selectivity towards ester was obtained over the AlCl3/SiO2 catalyst. DPPH radical scavenging test shows that the ester exhibits good antioxidant activity.

The Effect of Alkaline Treatment to the Structure of ZSM5 Zeolites Octaviani, Savitri; Krisnandi, Yuni K.; Abdullah, Iman; Sihombing, Riwandi
Makara Journal of Science Vol. 16, No. 3
Publisher : UI Scholars Hub

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Synthesis of Zr/La-BTC Bimetallic Metal-Organic Framework (MOF) for Oleic Acid Esterification Zulys, Agustino; Adawiah, Adawiah; Suminta, Tiara Amalia; Abdullah, Iman; Fadhilla, Rizkha; Nasruddin, Nasruddin; Mabuchi, Takuya
Jurnal Kimia Valensi Jurnal Kimia VALENSI, Volume 10, No. 1, May 2024
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v10i1.37621

Biodiesel plays an essential role in renewable energy as an alternative fuel to tackle the challenges of global warming, environmental degradation, and alternative fossil fuels. Oleic acid can be converted into biodiesel by the esterification process, which employs heterogeneous catalysts such as metal-organic frameworks (MOF). In this study, Zr/La-BTC MOFs were used as different kinds of catalysts to change oleic acid into biodiesel. The characterization results of Zr-BTC, La-BTC, and Zr/La-BTC using FTIR and XRD show that the MOF has been successfully formed. The crystallite sizes for La-BTC, and Zr/La-BTC MOFs are 15.7407 nm and 39.0392 nm, respectively. The surface area of Zr-BTC, La-BTC, and Zr/La-BTC MOFs are 167.101 m2/g, 12.328 m2/g, and 4.764 m2/g. The morphology of Zr-BTC MOF using SEM is irregular, La-BTC is rod-shaped crystal, and Zr/La-BTC is like a knot bond with a narrow waist. The most optimal reaction was obtained at a 5% (w/w) catalyst dosage of total oleic acid and methanol (1:60 mol), 65 °C, and a reaction time of 4 hours, producing 78.11% oleic acid conversion. GC-MS analysis identified that the biodiesel contains oleic acid, palmitic acid, methyl oleate, and methyl palmitate.

Amine-modified Ni-DOBDC MOF for CO2 capture: CO2 adsorption capacity and reusability Fahriansyah, Irsan; Khatrin, Irena; Abdullah, Iman; Krisnandi, Yuni Krisyuningsih
Environmental and Materials Vol. 2 No. 2: (December) 2024
Publisher : Institute for Advanced Science, Social, and Sustainable Future

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61511/eam.v2i2.2024.1431

Background: Anthropogenic carbon dioxide (CO₂) emissions have risen significantly due to the extensive use of fossil fuels, necessitating the development of effective CO₂ capture and conversion techniques. Adsorption using Metal-Organic Frameworks (MOFs) has shown great potential due to their high CO₂ adsorption capacity, particularly Ni-based MOFs. Enhancing their adsorption efficiency remains a key research focus to improve sustainability in CO₂ capture applications. Methods: Ni-based MOF (Ni-DOBDC) was synthesized using the solvothermal method, employing DMF as the solvent and 2,5-dihydroxyterephthalic acid (DOBDC) as the organic ligand. To enhance CO₂ adsorption capacity, Ni-DOBDC was further modified with ethylenediamine (EDA) via post-synthetic modification. Structural characterization was performed using XRD, confirming similarity to the Ni-DOBDC reference (CCDC 288477), and FTIR, which showed enhanced absorbance peaks. SEM-EDX analysis revealed a flower-like morphology with an average particle size of 0.75 μm. CO₂ adsorption tests were conducted on Ni-DOBDC and EDA/Ni-DOBDC (10%) using the titration method under controlled conditions. Findings: The CO₂ adsorption capacity of Ni-DOBDC and EDA/Ni-DOBDC was tested at 70°C with a CO₂ concentration of 50% in N₂. EDA modification significantly improved CO₂ adsorption capacity, with EDA/Ni-DOBDC achieving 9.95 mmol g⁻¹ compared to pristine Ni-DOBDC’s 6.44 mmol g⁻¹. However, Ni-DOBDC exhibited better regeneration ability in a three-cycle reusability test, likely due to EDA leaching during regeneration. Conclusion: EDA-modified Ni-DOBDC demonstrates enhanced CO₂ adsorption capacity, making it a promising material for CO₂ capture applications. However, its reduced regeneration stability suggests the need for further optimization to improve long-term performance. Future studies should explore strategies to minimize EDA leaching while maintaining high adsorption efficiency. Novelty/Originality of this article: This study provides new insights into improving Ni-based MOF performance for CO₂ capture through post-synthetic modification with EDA. The findings highlight a trade-off between increased adsorption capacity and material stability, emphasizing the need for further refinement in MOF functionalization strategies.

Harnessing Copper's Potential: A Review of Cu-Based Catalysts for Glycerol Conversion Ahmed, Sabeel; Abdullah, Iman; Krisnandi, Yuni Krisyuningsih
Bulletin of Chemical Reaction Engineering & Catalysis 2025: BCREC Volume 20 Issue 2 Year 2025 (August 2025)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20341

The increasing depletion of fossil fuel reserves and environmental concerns have accelerated the search for sustainable alternatives, leading to the utilization of biodiesel as a renewable energy source. Glycerol, a key byproduct of biodiesel production, has been extensively investigated for conversion into value-added compounds such as lactic acid, acrylic acid, and 1,2-propanediol (1,2-PDO). Copper-based catalysts have gained popularity due to their low cost, high catalytic efficiency, and environmental friendliness. This review examines various copper-based catalytic systems for glycerol conversion through key processes such as hydrogenolysis, oxidation, steam reforming, and dehydration. The work focuses on how Cu-based bimetallic catalysts, such as Cu-Ni, Cu-Co, and Cu-Zn, improve reaction selectivity and conversion rates via synergistic interactions, better metal dispersion, and optimized redox properties. Furthermore, new catalyst manufacturing methods, such as ammonia evaporation, hydrothermal, and ion exchange approaches, have shown improved stability and reusability. The findings show that Cu-based catalysts successfully facilitate high glycerol conversion, with selective pathways favouring the generation of 1,2-PDO, lactic acid, and acrylic acid under optimal circumstances. However, catalyst deactivation caused by sintering and coke formation remains a concern. Future research should concentrate on creating stable, multifunctional catalysts, adding bio-derived support, and improving reaction conditions to increase long-term efficiency and industrial usability. This review emphasizes the potential of Cu-based catalytic systems in promoting glycerol valorisation and achieving a more sustainable chemical industry. Copyright © 2025 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis of Zr/La-BTC Bimetallic Metal-Organic Framework (MOF) for Oleic Acid Esterification Zulys, Agustino; Adawiah, Adawiah; Suminta, Tiara Amalia; Abdullah, Iman; Fadhilla, Rizkha; Nasruddin, Nasruddin; Mabuchi, Takuya
Jurnal Kimia Valensi Jurnal Kimia VALENSI, Volume 10, No. 1, May 2024
Publisher : Department of Chemistry, Faculty of Science and Technology Syarif Hidayatullah Jakarta State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v10i1.37621

Biodiesel plays an essential role in renewable energy as an alternative fuel to tackle the challenges of global warming, environmental degradation, and alternative fossil fuels. Oleic acid can be converted into biodiesel by the esterification process, which employs heterogeneous catalysts such as metal-organic frameworks (MOF). In this study, Zr/La-BTC MOFs were used as different kinds of catalysts to change oleic acid into biodiesel. The characterization results of Zr-BTC, La-BTC, and Zr/La-BTC using FTIR and XRD show that the MOF has been successfully formed. The crystallite sizes for La-BTC, and Zr/La-BTC MOFs are 15.7407 nm and 39.0392 nm, respectively. The surface area of Zr-BTC, La-BTC, and Zr/La-BTC MOFs are 167.101 m2/g, 12.328 m2/g, and 4.764 m2/g. The morphology of Zr-BTC MOF using SEM is irregular, La-BTC is rod-shaped crystal, and Zr/La-BTC is like a knot bond with a narrow waist. The most optimal reaction was obtained at a 5% (w/w) catalyst dosage of total oleic acid and methanol (1:60 mol), 65 °C, and a reaction time of 4 hours, producing 78.11% oleic acid conversion. GC-MS analysis identified that the biodiesel contains oleic acid, palmitic acid, methyl oleate, and methyl palmitate.

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