Single-site ruthenium catalyst supported on zeolite for CO2 hydrogenation to methyl formate.

Technologies for the transformation of atmospheric CO2 to useful chemicals, such as formic acid (FA), are essential to combatting excessive fossil fuel use and will need to be implemented on large scale. However, hydrogenation of CO2 to (base-free) FA is challenging for heterogeneous catalysts, due to the requirement for low temperatures enforced by the entropically unfavorable reaction of gases. By coupling CO2 hydrogenation to esterification, methyl formate (MF) can be prepared as a promising alternative platform chemical. Herein, a robust, heterogeneous single-metal-site catalyst was prepared and shown to achieve methanol hydrocarboxylation rates superior to nanoparticle catalysts (up to 18.3 ± 0.6 mmol hour-1 [Formula: see text]) while maintaining very high selectivity to MF (≥95%). Characterization reveals isolated, monodisperse Ru-nitrosyl complexes bound to three O-atoms of the zeolite framework, and the robust catalyst formed achieves a cumulative turnover number of more than 3500 over eight cycles. This work pushes the boundaries of supported single-site catalysts in CO2 utilization.