华南师范大学蓝亚乾团队开发出混合电催化全反应的氧化还原活性晶体配位催化剂。相关研究成果于2022年6月25日发表在《德国应用化学》。
二氧化碳还原反应（CO2RR）与热力学上更有利的阳极氧化反应耦合的混合CO2电还原，被认为是提高氧化还原产物总价值和能量转换效率的重要策略。
该文首次建立了含活性氧化位点的Ni 8-TET、含活性还原位点的Ni TPP和含氧化还原活性位点的PCN-601的混合电催化全反应配位催化剂模型体系。与其他两种化合物相比，PCN-601在FE-HCOOH和FE-CO含量均大于90%的情况下，可以完成甲醇阳极氧化反应和CO2阴极还原反应。此外，由于金属卟啉的光敏性，PCN-601的性能可以在光照下进一步提高（FE-HCOOH在1.8-2.5 V下超过90%，FE-CO在2-2.4 V下接近100%），这是第一个能够同时完成氧化和还原反应的晶体配位催化剂。
DFT计算表明，电场作用下，卟啉中Ni 8团簇向Ni离子的电子转移，提高了Ni 8团簇的氧化性和金属卟啉的还原性，从而改善了PCN-601的电催化性能。值得注意的是，这是首次报道使用一种晶体配位催化剂来实现混合电催化全反应。
此外，该项工作作为一个定义良好的模型系统，为建立混合CO2电还原反应的高效催化剂提出了新的设计思路。
附：英文原文
Title: Redox-Active Crystalline Coordination Catalyst for Hybrid Electrocatalytic Full Reaction
Author: Sheng-Nan Sun, Long-Zhang Dong, Jia-Ru Li, Jing-Wen Shi, Jiang Liu, Yi-Rong Wang, Qing Huang, Ya-Qian Lan
Issue&Volume: 2022-06-25
Abstract: Hybrid CO 2 electroreduction in which carbon dioxide reduction reaction (CO 2 RR) is coupled with a thermodynamically more favorable anodic oxidation reaction is recognized as a very important strategy to improve the total value of redox products and energy conversion efficiency. In this work, a coordination catalyst model system for hybrid electrocatalytic full reaction, including Ni 8 -TET with active oxidation sites, Ni-TPP with active reduction sites and PCN-601 with redox-active sites, was established for the first time. Compared with the other two compounds, PCN-601 can complete both anodic methanol oxidation reaction and cathodic CO 2 RR with FE HCOOH and FE CO over 90%. Furthermore, due to the photosensitivity of metalloporphyrins, the performances of PCN-601 can be further improved with light irradiation (FE HCOOH over 90% at 1.8 - 2.5 V and FE CO nearly 100% at 2 - 2.4 V), which is the first crystalline coordination catalyst that can complete oxidation and reduction reactions, simultaneously. DFT calculation shows that the electrons transferring from Ni 8 clusters to Ni ions in the porphyrin under electric fields results in the raised oxidability of Ni 8 clusters and raised reducibility of metalloporphyrin, which is responsible for the improved electrocatalytic performance of PCN-601. Significantly, it is the first report to use one crystalline coordination catalyst to achieve the hybrid electrocatalytic full reaction. Moreover, this work serving as a well-defined model system puts forward a new design idea for establishing efficient catalysts for hybrid CO 2 electroreduction reaction.
DOI: 10.1002/anie.202207282
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202207282
