Optimizing Ceria Promotion in Ni-Based Molecular Sieve Catalysts for Enhanced Hydrogen Production via Methane Partial Oxidation

Methane is one of the potent greenhouse gas which contributes to global warming deadly. Its emission cannot be stopped as it comes from various natural wetlands and anaerobic decomposition processes. Methane can be partially oxidized with a Ni-stabilized CBV20A molecular sieve (SiO ₂ /Al ₂ O ₃ = 20) to produce hydrogen-rich syngas. The Ni catalyst is located at charge compensation sites and inside the molecular sieve's pores. The catalysts are characterized by X-ray diffraction, surface area & porosity, FTIR, Raman spectroscopy, thermogravimetry analysis, transmission electron microscopy, and temperature programmed reduction/desorption/oxidation techniques. It was revealed that 2 wt.% ceria addition over 5Ni/CBV20A induced higher surface area and total active sites than 1 wt.% ceria promoted 5Ni/CBV20A. Over 5Ni2Ce/CBV20A, the concentration of active sites obtained from "NiO under moderate interaction" is at its peak. The metal-support interaction is further enhanced by the periodic exposure of hydrogen and oxygen during POM. 5Ni2Ce/CBV20A exhibits 2.5 H ₂ /CO, 65% H ₂ yield, and 65% CH ₄ methane conversion. High catalytic activity and the generation of hydrogen-rich syngas demonstrate the potential of Ni-based catalysts supported on a molecular sieve with a Ce promoter for POM.