Progress and development of biochar as a catalyst for hydrogen production

Abstract

The recent progress of the biochar application as a catalyst for the production of hydrogen has been presented in this review. Biochar is a carbon-rich material, which can be produced through different thermochemical conversions (pyrolysis, gasification, and hydrothermal carbonization) using various feedstocks. Biochar has gained attention as a possible catalyst for the production of hydrogen in recent years. It has a distinctive structure and multiple functions and can be accessed widely. The utilization of biochar as a catalyst can significantly improve the hydrogen yield and quality, showing improved catalytic activity and thermal stability. The physiochemical characteristics of biochar are also affected by the different types of feedstocks. Furthermore, the biochar performance can be increased as a catalyst when it is modified with alkali, acid, metal ions, carbonaceous materials, oxidants, purging of gas, and steam. This review presents an overview of the feedstock, production, modification, and characterization methods of the biochar, followed by an elaborate discussion on the application of biochar as a catalyst. This paper addresses the current development of biochar as a catalyst/support for hydrogen production in thermochemical techniques, photocatalytic water splitting, dark fermentation, and methane steam reforming. Overall, biochar catalyst has the potential for a cleaner and more effective energy system.