Catalytic decomposition of methane over enteromorpha prolifera-based hierarchical porous biochar

Abstract

Biochar is a potential catalyst for methane decomposition (CMD) owing to its environmental-friendly and application prospects. In this work, the hierarchical porous biochar was prepared by carbonization and H3PO4 activation using Enteromorpha prolifera (EP) as precursor, respectively. The results show that when the ratio of H3PO4/EP is 1.5, the maximum CH4 conversion is 46%, along with hydrogen output of 396 mmol/gcat, which is 5.8 times as that of the unactivated biochar. The characterization results by XPS, Raman, SEM and HRTEM indicate that P element is inserted in carbon layer in the form of C–O–P, resulting in lattice distortion of carbon layer and larger defect density, and C–O–P plays a dominant role in initial CH4 conversion. The mesopores formed by H3PO4 activation alleviate the influence of the deposited carbon on the catalyst and decrease the deactivation rate, thereby exhibiting better performance in CMD.