Regulating the *OCCHO intermediate pathway towards highly selective photocatalytic CO2 reduction to CH3CHO over locally crystallized carbon nitride
Regulating the *OCCHO intermediate pathway towards highly selective photocatalytic CO2 reduction to CH3CHO over locally crystallized carbon nitride
复制标题
调节 OCCHO 中间途径，在局部结晶氮化碳上实现高选择性光催化 CO2 还原为 CH3CHO
DOI：
10.1039/d1ee02073k
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发表时间：
2021-11-16
影响因子：
32.5
通讯作者：
Wang, Fuxian
中科院分区：
文献类型：
--
作者：
Liu, Qiong;Cheng, Hui;Wang, Fuxian
CO2光催化转化为CH3CHO越来越受到人们的关注，但在整个过程中面临着形成C-C键和保持C=O键完整的巨大挑战。在这里，我们报道了在温和的条件下，使用改性的聚碳氮化物(PCN)选择性地将CO2光催化氢化为CH3CHO。该催化剂的光催化活性为1814.7µmolh(-1)g(-1)，CH3CHO生成的选择性高达98.3%，在385 nm处的量子效率为22.4%，超过了目前最先进的二氧化碳光催化剂。在局部结晶的PCN上促进*OCCHO中间体的形成是导致高选择性CH3CHO生成的关键因素。局部结晶的PCN有利于自发的C-C偶联，而不是CHO质子化，从而阻止了甲醛的形成。这项工作为设计用于高选择性和可持续地将CO2转化为CH3CHO的碳氮化物提供了新的策略。
Photocatalytic conversion of CO2 to CH3CHO is of increasing interest but confronts the significant challenges of forming C-C bonds and keeping the C=O bond intact throughout the process. Here, we report the selective photocatalytic hydrogenation of CO2 to CH3CHO using a modified polymeric carbon nitride (PCN) under mild conditions. The locally crystallized PCN offers a photocatalytic activity of 1814.7 mu mol h(-1) g(-1) with a high selectivity of 98.3% for CH3CHO production and a quantum efficiency of 22.4% at 385 nm, outperforming all the state-of-art CO2 photocatalysts. The promoted formation of the *OCCHO intermediate on the locally crystallized PCN is disclosed as the key factor leading to the highly selective CH3CHO generation. The locally crystallized PCN favors spontaneous C-C coupling towards *OCCHO formation rather than *CHO protonation, thus preventing HCHO formation. This work provides a new strategy for designing carbon nitrides for highly selective and sustainable conversion of CO2 to CH3CHO.