CO-free hydrogen production from decomposition of formic acid over Au/Al2O3 catalysts doped with potassium ions

Abstract

Doping of a 2.5wt.% Au/Al2O3 catalyst with potassium ions (3wt.%) leads to a significantly increased rate by >1 order of magnitude of decomposition of formic acid at 358K as compared to an undoped catalyst with the same mean Au particle size (2.6nm). The doped catalyst gave stable and CO-free (<10ppm CO) hydrogen production. The mechanism of the reaction changed. This was provided by a significantly increased content of a reaction intermediate – formate ions (HCOO−) controlled by K+ counterions in formic acid condensed in the pores of the catalyst.