Wang Fangyuan, Gu Yuming, Tian Bailin, Sun Yuxia, Zheng Lifeng, Liu Shengtang, Wang Yiqi, Tang Lingyu, Han Xiao, Ma Jing, Ding Mengning
Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
J Phys Chem Lett. 2023 Mar 16;14(10):2674-2683. doi: 10.1021/acs.jpclett.3c00103. Epub 2023 Mar 9.
Replacing the oxygen evolution reaction (OER) with water-assisted oxidation of organic molecules represents a promising approach for achieving sustainable electrochemical biomass utilization. Among numerous OER catalysts, spinels have received substantial attention due to their manifold compositions and valence states, yet their application in biomass conversions remains rare. Herein, a series of spinels were investigated for the selective electrooxidation of furfural and 5-hydroxymethylfurfural, two model substrates for versatile value-added chemical products. Spinel sulfides universally exhibit superior catalytic performance compared to that of spinel oxides, and further investigations show that the replacement of oxygen with sulfur led to the complete phase transition of spinel sulfides into amorphous bimetallic oxyhydroxides during electrochemical activation, serving as the active species. Excellent values of conversion rate (100%), selectivity (100%), faradaic efficiency (>95%), and stability were achieved via sulfide-derived amorphous CuCo-oxyhydroxide. Furthermore, a volcano-like correlation was established between their BEOR and OER activities based on an OER-assisted organic oxidation mechanism.
用水辅助有机分子氧化取代析氧反应（OER）是实现可持续电化学生物质利用的一种有前景的方法。在众多OER催化剂中，尖晶石因其多样的组成和价态而受到广泛关注，但其在生物质转化中的应用仍然很少。在此，研究了一系列尖晶石用于糠醛和5-羟甲基糠醛的选择性电氧化，这两种是用于多种增值化学产品的模型底物。与尖晶石氧化物相比，尖晶石硫化物普遍表现出优异的催化性能，进一步研究表明，在电化学活化过程中，用硫取代氧导致尖晶石硫化物完全相转变为非晶态双金属羟基氧化物，作为活性物种。通过硫化物衍生的非晶态CuCo-羟基氧化物实现了转化率（100%）、选择性（100%）、法拉第效率（>95%）和稳定性的优异值。此外，基于OER辅助的有机氧化机制，在其BEOR和OER活性之间建立了类似火山的相关性。
