Catalytic decomposition of methane: Ni-promoted perovskite oxide catalysts for turquoise hydrogen and carbon nanomaterials Co-production

This study investigates the effectiveness of catalytic decomposition of methane for producing turquoise hydrogen and solid carbon nanomaterials. The focus is on developing cost-effective and high-performance Nickel (Ni)-promoted perovskite oxide catalysts. A series of transition metal, Ni-promoted (La0.75Ca0.25)(Cr0.5Mn0.5)O3-δ (LCCM) catalysts have been successfully prepared using water-based gel-casting technology. These catalysts are designed to decompose methane into turquoise hydrogen and carbon nanomaterials, achieving negligible CO2 emissions. X-ray diffraction results indicate that the solubility of Ni at the B-site of LCCM perovskite is limited, x ≤ 0.2. Field Emission Scanning Electron Microscopy analysis of xNi-LCCM, calcined at 1050 °C for ten h in the air, confirms severe catalyst sintering with excess nickel oxide distributed around the LCCM particles. At a 750 °C operating temperature, a Ni to LCCM molar ratio of 1.5 yields a maximum carbon output of 17.04 gC/gNi. Increasing the molar ratios to 2.0 and 2.5 results in carbon yields of 17.17 gC/gNi and 17.63 gC/gNi, respectively, showing minor changes. The morphology of the carbon nanomaterials is unaffected by the molar ratio of NiO promoter to LCCM and remains nearly the same within the scope of this study.