Hydrogen production from chemical looping reforming of methane: A screening of Ni-based oxygen carriers

The simultaneous increase in energy use and CO 2 emissions poses a serious environmental threat. Efficient technologies that produce low-carbon energy vectors from methane through CO 2 recycling offer promising solutions. Hydrogen, a lightweight energy vector with high energy content, ease of storage, and large-scale production potential, emits no direct pollutants and can be generated from various low-carbon sources. Chemical looping technologies are effective for hydrogen production due to their high energy efficiency and inherent CO 2 capture. This study investigates chemical looping technologies for hydrogen production through multiple redox cycles, alternating methane fuel steps with oxidation steps in air or CO 2 to restore the catalysts and remove carbon. For this reason, five nickel-based catalysts were tested: Ni coprecipitated with cerium oxide, Ni impregnated on lab-made ceria, NiMgAl and NiCaAl mixed oxides from hydrotalcite-like precursors, and a LaNi 0.8 Co 0.2 O 3 perovskite oxide. Results show hydrogen production efficiency and catalyst stability are strongly influenced by the oxidation atmosphere as well as by the materials redox properties and the nickel chemical environment. • Chemical Looping Reforming is an efficient process for hydrogen production. • Use of CO 2 in the oxidation step permits the production of CO and utilization of CO 2 . • Both the performance and stability of Ni in hydrogen production are a function of the Ni environment in the oxidic system. • When NiCaAl (exHT) was used as the catalyst, reoxidation with CO 2 resulted in increased activity and stability.