西北工业大学张健团队报道了去质子化的2-噻唑咪唑作为选择性乙炔加氢的无金属电催化剂。相关论文于2024年4月19日发表在《自然—化学》。

无金属催化剂提供了传统金属基电催化剂的理想替代方案。然而，具有明确活性位点的无金属催化剂很少表现出像金属基材料那样有前景的活性。

该文报道了2-硫代咪唑作为一种有效的无金属催化剂，用于乙炔选择性电催化加氢制乙烯。在碱性条件下，2-硫代咪唑的巯基和亚氨基会自发脱质子化为二胺离子。脱质子化富集了2-硫代咪唑中吡啶N位的负电荷，通过σ-构型增强了对亲电乙炔的吸附。乙烯偏电流密度和各种咪唑衍生物中吡啶N位点的负电荷呈火山关系。因此，去质子化的2-硫代咪唑表现出与Cu和Pd等金属基催化剂，具有竞争力的乙烯偏电流密度和法拉第效率。

该项工作突出了无金属分子在电催化中的可调谐性和有前途的潜力。

附：英文原文

Title: Deprotonated 2-thiolimidazole serves as a metal-free electrocatalyst for selective acetylene hydrogenation

Author: Zhang, Lei, Bai, Rui, Lin, Jin, Bu, Jun, Liu, Zhenpeng, An, Siying, Wei, Zhihong, Zhang, Jian

Issue&Volume: 2024-04-19

Abstract: Metal-free catalysts offer a desirable alternative to traditional metal-based electrocatalysts. However, metal-free catalysts, featuring defined active sites, rarely show activities as promising as metal-based materials. Here we report 2-thiolimidazole as an efficient metal-free catalyst for selective electrocatalytic hydrogenation of acetylene into ethylene. Under alkaline conditions, the sulfhydryl and imino groups of 2-thiolimidazole are spontaneously deprotonated into dianions. Deprotonation thus enriches the negative charges of pyridinic N sites in 2-thiolimidazole to enhance the adsorption of electrophilic acetylene through the σ-configuration. Ethylene partial current densities show a volcano relationship with the negative charges of the pyridinic N sites in various imidazole derivatives. Consequently, the deprotonated 2-thiolimidazole exhibits an ethylene partial current density and faradaic efficiency competitive with metal-based catalysts like Cu and Pd. This work highlights the tunability and promising potential of metal-free molecules in electrocatalysis.

DOI: 10.1038/s41557-024-01480-6

Source: https://www.nature.com/articles/s41557-024-01480-6