Heng Jin-Meng, Zhu Hao-Lin, Zhao Zhen-Hua, Yu Can, Liao Pei-Qin, Chen Xiao-Ming
MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional Materials, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China.
Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing 100049, China.
J Am Chem Soc. 2023 Oct 4;145(39):21672-21678. doi: 10.1021/jacs.3c08571. Epub 2023 Sep 21.
It is challenging and important to achieve high performance for an electrochemical CO reduction reaction (eCORR) to yield CH under neutral conditions. So far, most of the reported active sites for eCORR to yield CH are single metal sites; the performances are far below the commercial requirements. Herein, we reported a nanosheet metal-organic layer in single-layer, namely, [Cu(obpy)] (, Hobpy = 1-[2,2']bipyridinyl-6-one), possessing dicopper(I) sites for eCORR to yield CH in a neutral aqueous solution. Detailed examination of revealed high performance for CH production with a faradic efficiency of 82(1)% and a current density of ∼90 mA cm at -1.4 V . reversible hydrogen electrode (RHE). No obvious degradation was observed over 100 h of continuous operation, representing a remarkable performance to date. Mechanism studies showed that compared with the conventional single-copper sites and completely exposed dicopper(I) sites, the dicopper(I) sites in the confined space formed by the molecular stacking have a strong affinity to key C intermediates such as *CO, *CHO, and *CHO to facilitate the CH production, yet inhibiting C-C coupling.
在中性条件下实现电化学CO还原反应（eCORR）高产率生成CH具有挑战性且十分重要。到目前为止，大多数报道的用于eCORR生成CH的活性位点是单金属位点；其性能远低于商业要求。在此，我们报道了一种单层纳米片金属有机层，即[Cu(obpy)]（Hobpy = 1-[2,2']联吡啶基-6-酮），其具有双铜（I）位点，可在中性水溶液中通过eCORR生成CH。详细研究表明，在 -1.4 V（相对于可逆氢电极，RHE）时，该材料对CH生成具有高性能，法拉第效率为82(1)%，电流密度约为90 mA cm²。在连续运行100小时内未观察到明显降解，这代表了迄今为止的卓越性能。机理研究表明，与传统的单铜位点和完全暴露的双铜（I）位点相比，由分子堆积形成的受限空间中的双铜（I）位点对关键的C中间体如*CO、CHO和CH₂O具有很强的亲和力，有助于CH的生成，同时抑制C-C偶联。
