Synergistic effect between electric field and Ce-doped catalysts to promote hydrogen production from ammonia decomposition

Abstract

It is a good strategy to improve the combustion performance of ammonia in engines by onboard hydrogen mixing through ammonia decomposition. To utilize the exhaust heat from engines, a novel technology to decompose ammonia at low temperature (<350 °C) was studied, which is based on the synergistic effect between electric field and Ce-doped catalysts. A series of non-noble metals (Fe/Co/Ni) supported on Ce-doped ZrO2 semiconductor (CexZr1-xO2) were synthesized by solution combustion method to investigate the electric field-assisted catalytic activity. We achieved an ammonia conversion of 60% at 300 °C for Ni/Ce0.25Zr0.75O2 catalyst and the maximum energy efficiency is close to 20% for Fe/Ce0.25Zr0.75O2 catalyst with electric field. The synergistic effects of basicity enhancement and proton hopping between the electric field and Ce-doped catalysts were found by a series of characterizations. Electric field facilitated the generation of strong basic sites, which was beneficial to the recombinative desorption of nitrogen. And the proton hopping helped to reduce hydrogen poisoning.