Microenvironment Modulation of Single-Atom Ru in ZrSBA-15 for CO 2 Hydrogenation to Formic Acid.

The chemical microenvironment modulation of active sites holds promise for facilitating their catalytic performance. Herein, single-atom Ru anchored by ZrSBA-15 modified with diverse organic amine groups has been fabricated and enabled CO 2 hydrogenation to produce formic acid (FA) under mild conditions. However, the reaction cannot be achieved without the modification of organic amines. The functional groups as the microenvironment around Ru active sites effectively regulated the activity, in which Ru encapsulated in ZrSBA-15 bearing -NH 2 groups exhibited the highest activity, with turnover number (TON) and turnover frequency (TOF) values of 505 and 64 h -1 , respectively. Both characterization and experimental results validated that the functional group manipulated the adsorption capacity of the reactant, the electronic state of Ru and hydrophilicity/hydrophobicity of the materials, and thus the catalytic performance.