Formamide Electrosynthesis from Methanol and Ammonia in Water over Pr-Doped MnO 2 .

A rare earth element doping strategy is reported to boost the activity and enhance the stability of MnO 2 for selective formamide production through electrocatalytic oxidation coupling (EOC) of methanol and ammonia. MnO 2 doped with 1% Pr was selected as the best candidate with an optimized formamide yield of 211.32 μmol cm -2 h -1 , a Faradaic efficiency of 22.63%, and a stability of more than 50 h. The easier formation of Mn 6+ species and the lower dissolution rate of Mn species over Pr-doped MnO 2 revealed by in situ Raman spectra were responsible for the boosted formamide production and enhanced stability. In addition, a two-electrode flow electrolyzer was developed to integrate EOC with C 2 H 2 semihydrogenation for simultaneously producing value-added products in both the anode and cathode.