Effect of strontium on the performance of Ni/CBV20A catalyst in partial oxidation of methane for syngas and hydrogen production

Abstract

Converting methane into syngas via partial oxidation of methane (POM) is a promising energy-efficient technology given its exothermic nature. Active nickel-based catalysts suffer from deactivation by carbon deposition and sintering. This study explores the novel use of mordenite zeolite (CBV20A) as a catalytic support for nickel (Ni) and using strontium (Sr) as a promoter. Ni₅Sr_x/CBV20A samples with various Sr loadings were prepared and characterized using N₂-sorption, X-ray diffraction, H₂-temperature programmed reduction, temperature programmed desorption of CO₂, and Transmission Electron Microscopy. Sr addition improved NiO reducibility at lower temperature and boosted basicity, enhancing CH₄ conversion and H₂ yield. The optimal catalyst, Ni₅Sr₂/CBV20A, exhibited the highest performance with 72% CH₄ conversion, 47% H₂ yield, and 2.6 H₂/CO ratio at 700 °C and 14 400 mL g⁻¹ h⁻¹. Results show that at a high gas hourly space velocity (GHSV) of 72 000 mL g⁻¹ h⁻¹, a combustion and reforming reaction mechanism is preferred, while at a low GHSV of 14 400 mL g⁻¹ h⁻¹, a direct partial oxidation mechanism predominates.