Hydrogenation of CO₂ to Formate over Ruthenium Immobilized on Solid Molecular Phosphines

Abstract

Formic acid is a promising hydrogen storage medium and can be produced by catalytic hydrogenation of CO . Molecular ruthenium complexes immobilized on phosphine polymers have been found to exhibit excellent productivity and selectivity in the catalytic hydrogenation of CO under mild conditions. The polymeric analog of 1,2-bis(diphenylphosphino)ethane exhibited the highest activity and turnover numbers up to 13 170 were obtained in a single run. This catalyst was already active at 40 °C and with a catalyst loading of only 0.0006 mol %. Recycling experiments revealed a loss of activity after the first run, followed by a gradual decrease during the subsequent runs. This is attributed to a change in the catalytically active complex during the hydrogenation reaction. High selectivity towards formate and low leaching were maintained in the absence of CO formation. Based on the catalyst characterization, a mechanism for the CO hydrogenation is proposed.

Zinc Oxide Morphology‐Dependent Pd/ZnO Catalysis in Base‐Free CO2 Hydrogenation into Formic Acid

“…Among these, FA is an attractive product that can be easily generated via CO 2 hydrogenation reaction, which exhibits wide applications in leather tanning, silage preservation and hydrogen storage [21–23] . Many efforts have been devoted to produce FA with heterogeneous catalysts and Pd‐based catalysts are found to be the most promising [24–47] . The first reported Pd‐based heterogeneous catalyst was Pd black, found by Bredig and Carter in 1914 [35] .…”

Efficient synthesis of highly dispersed ultrafine Pd nanoparticles on a porous organic polymer for hydrogenation of CO2 to formate

“…The concept of insoluble matrix based immobilization of homogenous catalysts for conversion of FA by hydrogenation of CO 2 is based on the maintenance of activity of the catalyst as well as easy separation. [22][23][24][25] However, these catalysts suffer from various problems including deactivation of the catalyst, low turnover numbers and leaching of the metallic catalysts.…”

Enabling storage and utilization of low-carbon electricity: power to formic acid

“…30). 158 The XPS measurement of the resulting Ru@pdppe (127) confirmed the oxidation state of Ru as +2 and the TEM analysis revealed the absence of any NPs. Under 100 bar H2/CO2 (1:1) in the presence of K2CO3 in water, a maximum TON of 13170 was observed at 120 °C.…”