Establishment of a circular economy and carbon neutrality could be greatly aided by the sustainable use of biochar made from biomass waste. Biochar-based catalysts are essential for sustainable biorefineries and environmental protection because of their affordability, versatility, adaptable porosity structure, and thermal stability. It is simple to obtain biochar from a variety of solid waste categories, including plastics, municipal solid waste, food processing businesses, and agroforestry. High-performance carbon compounds derived from fossil fuels can be inexpensively replaced by biochar, which also has the added benefits of being environmentally benign and sustainable.

In the field of solid-state hydrogen storage, Magnesium hydride (MgH2) has received considerable attention globally due to its impressive hydrogen storage properties i.e., high hydrogen storage capacity (7.6 wt%), easy availability and low cost. However, major constraint in its practical application is the high dehydrogenation temperature due to stable thermodynamics and slow kinetics. Many transition-metal-based catalyst have been investigated to overcome this problem, but they usually agglomerate after a few cycles and grow at high temperatures, affecting overall catalytic performance. Carbon based materials can effectively address this problem by strengthening the interface between the catalyst and MgH2 which further prevent sintering and agglomeration of the catalyst particles during continuous hydrogenation and dehydrogenation process. Carbon network base also provides channels for fast hydrogen diffusion, improves thermal conductivity of the sample, and sometimes acts as a catalyst itself which may significantly increase the hydrogen sorption performance and cyclic stability of MgH2 based composites.