Roy Prodyut, Pramanik Anup, Sarkar Pranab
Department of Chemistry, Visva-Bharati University, Santiniketan-731235, India.
Department of Chemistry, Sidho-Kanho-Birsha University, Purulia-723104, India.
J Phys Chem Lett. 2021 Nov 11;12(44):10837-10844. doi: 10.1021/acs.jpclett.1c03242. Epub 2021 Nov 2.
Searching for an alternative nonhazardous catalyst for direct urea synthesis that avoids the traditional route of NH synthesis followed by CO addition is a challenging field of research nowadays. Based on first-principles calculations, we herein propose a novel electrocatalyst comprising of totally nonmetal earth abundant elements (dual-Si doped g-CN sheet) which is capable of activating N and making it susceptible toward direct insertion of CO into the N-N bond, producing NCON which is the precursor for urea production by direct coupling of N and CO followed by multiple proton coupled electron transfer processes. Remarkably, the calculated onset potential for urea production is much less than that of NH synthesis and hydrogen evolution reactions, and also the faradaic efficiency is nearly 100% for production urea over ammonia, which promotes exclusive electrocatalytic urea synthesis by suppressing the NH synthesis as well as hydrogen evolution reactions.
寻找一种用于直接尿素合成的替代性无危险催化剂，以避免传统的先合成氨再添加一氧化碳的路线，是当今一个具有挑战性的研究领域。基于第一性原理计算，我们在此提出一种新型电催化剂，它完全由地球上储量丰富的非金属元素组成（双硅掺杂的石墨相氮化碳片），这种电催化剂能够活化氮，并使其易于将一氧化碳直接插入氮 - 氮键中，生成NCON，这是通过氮和一氧化碳直接偶联并随后进行多个质子耦合电子转移过程来生产尿素的前体。值得注意的是，计算得出的尿素生成起始电位远低于氨合成和析氢反应的起始电位，而且在生成尿素方面的法拉第效率相对于氨而言接近100%，这通过抑制氨合成以及析氢反应促进了专一性的电催化尿素合成。
