Catalytic hydrogen combustion over supported metal catalysts; comparison and kinetic study

Catalytic H2 combustion (CHC) is an efficient way to mitigate H2 slip from industrial processes, overcoming the explosion and NOx emission risks. Although Pt-based catalysts are state-of-the-art catalysts, little is known about the CHC catalytic activity of other transition metals (TMs) and their reaction kinetics. Well-dispersed nano-sized M-γAl2O3 (M = Pt, Ru, Co, Ni, Mo) catalysts are synthesized and characterized with spectroscopic and electron microscopy methods. During the CHC reaction, a competitive reaction between O2, H2 and the catalyst is observed, which leads to partial or complete oxidation of the TMs. Stable CHC performance is attained for Ru-γAl2O3 and Co-γAl2O3 catalysts over 45 h. The kinetically controlled region is determined using a new data acquisition approach. The activation energy and pre-exponential factor are compared between M-γAl2O3 catalysts based on the Arrhenius model. This knowledge is highly valued and allows the design of supported catalysts and optimize the CHC reaction in various applications with different requirements.