Hong Young Hyun, Jia Xiaofan, Stewart-Jones Eleanor, Kumar Abhishek, Wedal Justin C, Alvarez-Hernandez Jose L, Donley Carrie L, Gang Albert, Gibson Noah J, Hazari Nilay, Houck Madison, Jeon Sungho, Kim Jongbeom, Koh Hyeongjun, Mayer James M, Mercado Brandon Q, Nedzbala Hannah S, Piekut Nicole, Quist Christine, Stach Eric, Zhang Yihui
Department of Chemistry, Yale University, P. O. Box 208107, New Haven, CT, 06520, USA.
Department of Chemistry and Center for Nano Materials, Sogang University, Seoul 04107, Republic of Korea.
Chem. 2025 Jul 10;11(7). doi: 10.1016/j.chempr.2025.102462. Epub 2025 Mar 7.
The selective reduction of to formate using molecular catalysts immobilized on high surface area porous silicon is described. Manganese complexes of the form (bpy)Mn(CO)Br (bpy = 2,2'-bipyridine) were prepared with silatrane groups on the bpy ligand for attachment to oxide-coated porous silicon (SiO-porSi). SiO-porSi wafers were formed by heating hydrogen-terminated p-type porous silicon wafers under air and the manganese complexes were immobilized on SiO-porSi by heating at 80 °C. The resulting Mn@SiO-porSi photoelectrodes are photoelectrocatalysts for reduction in acetonitrile containing 2.0 M triethylamine and 2.0 M isopropanol, yielding formate with high selectivity (>96%) and current density (~0.6 mA/cm), excellent reproducibility, and a photovoltage of 280 mV at -1.75 V (versus ferrocenium/ferrocene) under 1 sun illumination. The applied potential is close to the equilibrium potential for reduction to formate. This work presents rare examples of immobilized molecular catalysts for reduction to formate, and the first on semiconducting silicon.
本文描述了使用固定在高比表面积多孔硅上的分子催化剂将二氧化碳选择性还原为甲酸盐的过程。制备了(bpy)Mn(CO)Br形式的锰配合物（bpy = 2,2'-联吡啶），其中bpy配体上带有硅氮烷基团，用于附着在氧化物包覆的多孔硅（SiO-porSi）上。通过在空气中加热氢终止的p型多孔硅晶片形成SiO-porSi晶片，并通过在80°C下加热将锰配合物固定在SiO-porSi上。所得的Mn@SiO-porSi光电极是用于在含有2.0 M三乙胺和2.0 M异丙醇的乙腈中还原二氧化碳的光电催化剂，以高选择性（>96%）和电流密度（~0.6 mA/cm）产生甲酸盐，具有出色的重现性，并且在1个太阳光照下，在-1.75 V（相对于二茂铁鎓/二茂铁）时的光电压为280 mV。施加的电位接近二氧化碳还原为甲酸盐的平衡电位。这项工作展示了将二氧化碳还原为甲酸盐的固定化分子催化剂的罕见实例，并且是第一个在半导体硅上的实例。
