Improvement of the stability of a ZrO 2-modified Ni–nano-CaO sorption complex catalyst for ReSER hydrogen production

Abstract

A Ni–nano-CaO sorption complex catalyst was modified with ZrO 2 to improve its stability for use in hydrogen production from steam methane reforming (SMR). Nano-ZrO 2 was introduced into a support containing nano-CaCO 3 and Al 2O 3. The sorption complex catalyst, ZrO 2–Ni–nano-CaO, was prepared by infusing Ni into the ZrO 2–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 ZrO 2-modified sorption complex catalyst could achieve 20 cyclic runs of ReSER hydrogen production, while the sorption complex catalyst without the ZrO 2 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 ZrO 2 could prevent the formation of NiAl 2O 4 in the sorption complex catalyst, which we believe to be the main cause of the improvement in the catalyst stability.