A-site defects boosted exsolution on (La0.5Ca0.5)(1-α)Ni0.06Ti0.94O3-δ for ethanol steam reforming

With global industrialization and population increase, the constraints of fossil fuels in terms of price and environmental protection necessitate the development of alternate energy sources. Ethanol reforming, as a non-fossil-originated hydrogen production process, has become an industrially promising reaction. In this work, perovskite titanate (La0.5Ca0.5)(1-α)Ni0.06Ti0.94O3-δ with different A-site deficiency was synthesized via a modified Pechini method. Orthorhombic titanates with grain size of 200 to 500 nm were obtained with nickel cooperated into the frameworks. The extent of A-site deficiency influences the size and population of exsolved nickel particles. Higher A-site defects would greatly induce the exsolution of nickel, thus promoting the catalytic activity in ethanol steam reforming reaction. La0.4Ca0.4Ni0.06Ti0.94O3-δ sample showed an outlet composition that was closed to thermodynamic equilibrium under S/C = 3 and WHSV = 8.8 gethanol/(gcat·h). The metal agglomeration was inhibited during 8-hour reforming at high temperatures, while the deactivation during the stability test was mainly due to the formation of graphite carbon.