Improvement of the stability of a ZrO2-modified Ni–nano-CaO sorption complex catalyst for ReSER hydrogen production

A Ni–nano-CaO sorption complex catalyst was modified with ZrO2 to improve its stability for use in hydrogen production from steam methane reforming (SMR). Nano-ZrO2 was introduced into a support containing nano-CaCO3 and Al2O3. The sorption complex catalyst, ZrO2–Ni–nano-CaO, was prepared by infusing Ni into the ZrO2–nano-CaO support, followed by calcination. The catalyst was evaluated with a bench-scale fixed bed reactor under the following reaction conditions: a temperature of 600 °C, a steam–carbon mole ratio of 4:1, a gas hourly space velocity of 1800 h−1, and a regeneration temperature of 800 °C. The reaction was performed under an atmosphere of nitrogen. The ZrO2-modified sorption complex catalyst could achieve 20 cyclic runs of ReSER hydrogen production, while the sorption complex catalyst without the ZrO2 modification rapidly deactivated after three cyclic runs. Brunauer–Emmer–Teller analysis showed that the catalyst surface area of the new catalyst had increased. Furthermore, the addition of ZrO2 could prevent the formation of NiAl2O4 in the sorption complex catalyst, which we believe to be the main cause of the improvement in the catalyst stability.