Clean Water and Sanitation (SDG 6), Climate Action (SDG 13)
Reducing greenhouse gas through CO 2 hydrogenation to value-added chemicals Nyasha Makuve* 1 , James Darkwa 2 , Gift Mehlana 3 , and Banothile C. E. Makhubela 2 1 Chemistry Department, University of Botswana, Gaborone, Botswana 2 Research Centre for Synthesis and Catalysis, Department of Chemical Sciences, Auckland Park Kingsway Campus, University of Johannesburg, Johannesburg South Africa 3 Department of Chemical Technology, Midlands State University, Zimbabwe Carbon dioxide (CO 2 ) is a major contributor to the greenhouse effect and has an effect of trapping the sun’s heat which is presently observed in climate change phenomena [1], [2] . Reducing CO 2 emissions is an extensive and long-term task which involves finding strategies to reduce of the amount of CO 2 produced, storage of CO 2 and usage of CO 2 stored [3] . The utilization and transformation of CO 2 into value-added chemicals has attracted much attention in recent years thus, the development of efficient methods of CO 2 reduction such as catalytic hydrogenation which is highly desirable. Over the years a plethora of methods have been developed to utilize CO 2 as a C1 carbon source reagent for synthesis of important chemicals such as carboxylic acids, esters and lactones owing to its abundance and safety as compared to CO. Catalytic hydrogenation of CO 2 , which is known to have high kinetic and thermodynamic stability, is an important reaction that can be employed to reduce and utilize CO 2 to formic acid and methanol. Catalytic processes involving metal catalysts have been widely used in the chemical industry due to their reusability, intertwined and widespread applications. Cadmium(II) metal catalysts have been reported recently in homogenous transesterification reaction, heterogenous MOF-based catalysts and photocatalytic activity in semiconducting sulfides [4], [5] . As part of on-going work on CO 2 utilisation [6] , we have taken advantage of the chemical stability offered by the cadmium MOF under different solvent conditions and the high activity offered by nanoparticles towards CO 2 hydrogenation. Herein, we describe the synthesis and characterization of a cadmium metal-organic framework (MOF1) which was used as a support for Pd, Ni and Pt nanoparticles to form MOF1 nanoparticles composites which were fully characterized and investigated as pre-catalysts in hydrogenation of CO 2 to formate. Notably, this work demonstrates that the combination of nanoparticles and MOFs greatly enhances the catalytic activity of the active sites. Key words: CO 2 catalytic hydrogenation, heterogeneous catalysis, MOF, formate
References 1. W. Wang, S. P. Wang, X. B. Ma, and J. L. Gong, “Recent advances in catalytic hydrogenation of carbon dioxide,” Chem. Soc. Rev., vol. 40, no. 7, p. 3703, 2011, doi: 10.1039/c1cs15008a. 2. Y.-N. Li, R. Ma, L.-N. He, and Z.-F. Diao, “Homogeneous hydrogenation of carbon dioxide to methanol,” Catal. Sci. Technol., vol. 4, no. 6, p. 1498, 2014, doi: 10.1039/c3cy00564j. 3. M. Mikkelsen, M. Jørgensen, and F. C. Krebs, “The teraton challenge. A review of fixation and transformation of carbon dioxide,” Energy Environ. Sci., vol. 3, no. 1, pp. 43–81, 2010, doi: 10.1039/B912904A. 4. S. Mukherjee, in Sustainable Catalysis: With Non-endangered Metals, 2015, pp. 91–113. 5. Y. Venkateswarlu, S. R. Kumar and P. Leelavathi, Int. J. Ind. Chem., 2012, 3, 18. 6. N. Makuve, G. Mehlana, R. Tia, J. Darkwa, and B. C. E. Makhubela, “Hydrogenation of carbon dioxide to formate by α-diimine RuII, RhIII, IrIII complexes as catalyst precursors,” J. Organomet. Chem., vol. 899, pp. 1–14, 2019, doi: 10.1016/j. jorganchem.2019.120892.
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