Continuous Production of Hydrogen from Formic Acid Decomposition Over Heterogeneous Nanoparticle Catalysts: From Batch to Continuous Flow

Abstract

We investigate the continuous generation of hy-drogen via the low temperature (< 110 °C), additive-free dehydrogenation of formic acid over heterogeneous Pd/C. Through a combination of kinetic (batch and continuous), spectroscopic and mechanistic studies, we develop structure-activity-lifetime relationships for this process, and in doing so reveal that a combination of pore fouling and poisoning by formate ions result in deactivation of the catalyst during continuous operation. Although these factors result in extensive deactivation in Plug Flow mode, promising results can be obtained by minimizing the steady state concentration of formic acid by operating in a Continuous Stirred Tank reactor. In doing so, continuous operation of the system without loss of activity for over 2500 turnovers is achieved, at mild conditions and in the absence of stoichiometric additives.