Monitoring of catalytic dehydrogenation of formic acid by a ruthenium (II) complex through manometry

Abstract

A Ru-based polypyridine complex [Ru(2py-tpy)(DQN)Cl](PF6) ([Ru-(DQN)]) has been synthesised and employed as an active catalyst for the decomposition of formic acid. The activation energy required for the dehydrogenation of formic acid was 31.45 kJ/mol. The dehydrogenation of formic acid at pH 7.0 was also observed along with the CO2 gas. • The [Ru(2py-tpy)(DQN)Cl](PF6) complex has synthesized. • It has been employed as a catalyst for HCOOH decomposition. • H2 and CO2 was detected through GC. • The Ea for the dehydrogenation of formic acid was 31.45 kJ/mol. • The ΔG was estimated to be 81.33 kJ. • The gas pressure analysis was conducted by manometry. The [Ru(2py-tpy)(DQN)Cl](PF 6 ) ( [Ru-(DQN)] ) (Where 2,3-di(pyridin-2-yl) quinoxaline = DQN ) complex has been synthesised and employed for the dehydrogenation of the formic acid in the presence of sodium formate. The catalytic activity of the complex was studied at different temperatures and by varying the concentration of the acid, base, and complex. The catalytic gas evolutions were investigated using the differential manometry technique to avoid the ambiguities in back-pressure and burette methods. The activation energy required for the dehydrogenation of formic acid was 31.45 kJ/mol obtained from the Arrhenius plot, and ΔG was estimated to be 81.33 kJ from the Eyring plot. The catalyst shows the highest TOF at pH 7.0.