This review highlights the recent trends in the heterogeneous hydrogenation of CO ₂ to formic acid/formate.

One bottleneck in the realization of CO₂ conversion into value-added compounds is the lack of catalysts with both excellent activity and recyclability. Herein, a catalyst is designed for the hydrogenation of CO₂ to formate to boost up these features by considering the leaching pathway of previously reported heterogenized catalyst; the design strategy incorporates oxyanionic ligand(s) in the coordination sphere to provide a pathway for both preventing the deleterious interactions and assisting the heterolysis of H₂. The tailored heterogenized catalyst, [bpy-CTF-Ru(acac)₂]Cl, demonstrated excellent recyclability over consecutive runs with a highest turnover frequency of 22 700 h^–1, and produced a highest formate concentration of 1.8 M in 3 h. This work is significant in elucidating new principles for the development of industrially viable hydrogenation catalysts.

An integrated continuous CO₂ hydrogenation to formic acid process with trickle-bed reactor is developed using a heterogeneous Ru molecular catalyst.