Dual function NiMo/MgO catalyst for biogas valorization to syngas and carbon nanotubes

Abstract

The current transition from fossil energy to renewable energy presents a substantial challenge in the development of highly efficient catalytic conversion systems. This work presents a new dual-functional catalytic material capable of fully utilizing biogas as a renewable resource, based on a novel combination of dry reforming and catalytic decomposition of methane processes. A dual-function nickel-molybdenum (Ni–Mo) catalyst was produced by utilizing a simple and efficient impregnation process with optimized mass ratio between Ni and Mo. With a 1:0.5 ratio, the catalyst converted all CO2 (100% conversion) into syngas with a 97.6% yield and a 98.8% purity level and a H2/CO ratio higher than 3, demonstrating an impressive 98% CH4 transformation efficiency at 900 °C. This research reveals a significant finding that CO2 in the biogas feed improves the catalyst stability, even in the presence of carbon deposition on the catalyst surface. Additionally, the technique concurrently generates high-value carbon nanotubes (CNTs) at a rate of 0.37 gCNT/gCat-h. The tip-growth process of CNTs limits the coverage of the catalyst’s active sites while maintaining constant reaction efficiency. The compromise between catalytic activity and carbon formation is a substantial improvement by catalyst design. This study demonstrates a sustainable and effective biogas conversion method that integrates renewable energy use with the manufacture of valuable commodities, hence expanding opportunities in commercial biogas conversion technology. The catalyst’s dual serving capabilities, together with its remarkable endurance and suitability, indicate its potential for industrial-scale biogas applications.