具有不对称配位的双原子催化剂(DAC)对于增强电化学二氧化碳还原的益处和促进可持续发展至关重要。然而,DAC的合理设计仍然具有挑战性。在这里,我们合成了具有新型硫桥连Cu-S-Ni位点(命名为Cu-S-Ni/SNC)的原子分散催化剂,利用生物质羊毛角蛋白作为前体。羊毛角蛋白中丰富的二硫键克服了传统气相S配体蚀刻工艺的局限性,并能够一步形成S桥接位点。X射线吸收光谱(XAS)证实了具有N2Cu-S-NiN2部分的双金属位点的存在。在H细胞中,Cu-S-Ni/SNC在-0.65V相对于RHE显示98.1%的高CO法拉第效率。受益于金属位点和桥接硫原子之间的电荷调谐效应,在流动池中-1.00V时可实现550mAcm-2的大电流密度。此外,原位XAS,衰减全反射表面增强红外吸收光谱(ATR-SEIRAS),和密度泛函理论(DFT)计算表明Cu作为主要吸附位点是由Ni和S原子双重调节的,这增强了CO2活化并加速了*COOH中间体的形成。这种不对称双金属原子催化剂可能为原子材料的精确制备和性能调节开辟了新的能源应用途径。本文受版权保护。保留所有权利。
Double-atom catalysts (DACs) with asymmetric coordination are crucial for enhancing the benefits of electrochemical carbon dioxide reduction and advancing sustainable development, however, the rational design of DACs is still challenging. Herein, this work synthesizes atomically dispersed catalysts with novel sulfur-bridged Cu-S-Ni sites (named Cu-S-Ni/SNC), utilizing biomass wool keratin as precursor. The plentiful disulfide bonds in wool keratin overcome the limitations of traditional gas-phase S ligand etching process and enable the one-step formation of S-bridged sites. X-ray absorption spectroscopy (XAS) confirms the existence of bimetallic sites with N2Cu-S-NiN2 moiety. In H-cell, Cu-S-Ni/SNC shows high CO Faraday efficiency of 98.1% at -0.65 V versus RHE. Benefiting from the charge tuning effect between the metal site and bridged sulfur atoms, a large current density of 550 mA cm-2 can be achieved at -1.00 V in flow cell. Additionally, in situ XAS, attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), and density functional theory (DFT) calculations show Cu as the main adsorption site is dual-regulated by Ni and S atoms, which enhances CO2 activation and accelerates the formation of *COOH intermediates. This kind of asymmetric bimetallic atom catalysts may open new pathways for precision preparation and performance regulation of atomic materials toward energy applications.