Upgrading the low temperature water gas shift reaction by integrating plasma with a CuOx/CeO2 catalyst.

Plasma-catalytic WGS was upgraded under 150 °C low temperature and the underlying mechanisms were proposed by Experimental and theoretical results. [Display omitted] • Plasma-catalytic WGS reaction achieves 96% CO conversion at 150 °C. • In-situ experimental results reveal the participation of gaseous radicals. • DFT calculations propose a WGS reaction mechanism under plasma condition. • Microkinetic model clarify the enhancement by radicals and vibrational excitation. Low temperature WGS reaction is kinetically limited though it is thermodynamically favored. Herein, an outstanding synergistic effect between dielectric barrier discharge (DBD) plasma and non-precious CuO x /CeO 2 catalysts was observed to robustly accelerate the water gas shift (WGS) reaction at 150 °C (increase from 6% to 96% after plasma on). The apparent activation energy of the reaction was remarkablly diminished by plasma (69.6 to 15.0 kJ/mol). In-situ characterization experiments (e. g. OES and DRIFTS) revealed that the OH radicals generated by plasma-induced H 2 O dissociation was found to participate in the WGS reaction. In the furtherly study in DFT calculation and microkinetic modelling investigation, the OH radicals were proved to be one of the reasons for the giant increase in reaction rate. Besides, the vibrational excitation of reactants (e. g. CO) promoted by plasma could also reduce the reaction barriers of some crucial elementary reactions, thus accelerating the reaction rate. [ABSTRACT FROM AUTHOR]