Enhanced CO₂ conversion with CH₄ for greenfuel generation using coke-neutral nickel-loaded fibrous silica titania catalysts

This study reveals a groundbreaking advancement in utilizing carbon dioxide (CO₂) for syngas production through methane (CH₄) dry reforming using Fibrous Silica Titania (FST) as a support, loaded with different (1%, 3%, and 5%) nickel dosages. FST is distinguished by its fibrous structure, maintains a stable temperature, facilitates the confinement and dispersion of active metal, and is exceptionally effective at preventing carbon deposition. For a thorough examination of the new catalysts, characterization methods including XRD, FESEM, EDX mapping, N₂ physisorption, FTIR-KBr, H₂-TPR, and CO₂-TPD were employed. Importantly, TEM lattice fringes verified the existence of XRD peaks and planes of Ni (111), Ni (200), and TiO₂ (101). Aspects such as O-H stretching, Si-O-Si asymmetry, vibrations caused by external Si-OH groups, and Si-O-Si bending were identified using FTIR-KBr analysis. The study ingeniously identified the superior (3Ni/FST) catalyst, which exhibited moderate basicity sites on the CO₂-TPD at approximately 350 °C. The catalyst converted nearly 100% CH₄ at 750 °C with minimal coke production and 80% CO₂ at 850 °C. Surprisingly, the 3Ni/FST catalyst demonstrated remarkable stability during a 72 h TOS stability test at 650 °C, effectively preventing coke-forming side reactions such as CO disproportionation, CO hydrogenation, CO₂ and CH₄ cracking with syngas ratio around unity and little coke production. The FST support exhibited exceptional attributes for low temperature carbon neutral CH₄ reforming.