Cobalt telluride electrocatalyst for selective electroreduction of CO2 to value-added chemicals
Cobalt telluride electrocatalyst for selective electroreduction of CO2 to value-added chemicals
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DOI：
10.1007/s40243-022-00211-6
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发表时间：
2022-07
影响因子：
4.5
通讯作者：
Apurv Saxena;Harish Singh;M. Nath
中科院分区：
文献类型：
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作者：
Apurv Saxena;Harish Singh;M. Nath
最近对二氧化碳利用的重视使得有必要探索除了铜基体系之外的不同催化剂组合物，其可以在低应用潜力下显著改善对特定CO2还原产物的活性和选择性。在这项研究中，一个二元CoTe已被报道为一个有效的电催化剂，在中性pH值的环境条件下，在水介质中的CO2还原。CoTe显示出高法拉第效率和选择性的86.83和75%，分别为乙酸在非常低的电位为-0.25 V vs RHE。更有趣的是，C1产物如甲酸优先在略高的外加电位下形成，在-1.1 V vs RHE下达到547.24 μmol cm− 2 h − 1的高形成速率。CoTe表现出更好的CO2 RR活性时，与Co 3 O 4相比，这可以归因于催化活性的过渡金属中心的电化学活性增强，以及在催化剂表面上的中间体吸附的改善。虽然碲化物中阴离子电负性降低和晶格共价性改善增强了Co的电化学活性，但高d-电子密度改善了中间CO在催化剂位点上的吸附，从而导致在较低的施加电位下CO2还原和对C2产物的高选择性。CoTe还显示出稳定的CO2 RR催化活性50小时和低塔菲尔斜率（50.3 mV dec-1），表明更快的反应动力学和强大的功能。选择性地形成具有低能耗的附加值C2产品可以使这些催化剂与其他CO2捕获技术相结合，从而有助于关闭碳循环。
Recent emphasis on carbon dioxide utilization has necessitated the exploration of different catalyst compositions other than copper-based systems that can significantly improve the activity and selectivity towards specific CO2reduction products at low applied potential. In this study, a binary CoTe has been reported as an efficient electrocatalyst for CO2reduction in aqueous medium under ambient conditions at neutral pH. CoTe showed high Faradaic efficiency and selectivity of 86.83 and 75%, respectively, for acetic acid at very low potential of − 0.25 V vs RHE. More intriguingly, C1 products like formic acid was formed preferentially at slightly higher applied potential achieving high formation rate of 547.24 μmol cm−2h−1at − 1.1 V vs RHE. CoTe showed better CO2RR activity when compared with Co3O4, which can be attributed to the enhanced electrochemical activity of the catalytically active transition metal center as well as improved intermediate adsorption on the catalyst surface. While reduced anion electronegativity and improved lattice covalency in tellurides enhance the electrochemical activity of Co, high d-electron density improves the intermediate CO adsorption on the catalyst site leading to CO2reduction at lower applied potential and high selectivity for C2products. CoTe also shows stable CO2RR catalytic activity for 50 h and low Tafel slope (50.3 mV dec–1) indicating faster reaction kinetics and robust functionality. Selective formation of value-added C2products with low energy expense can make these catalysts potentially viable for integration with other CO2capture technologies thereby, helping to close the carbon loop.