Wang, et al (2024) Optimization of Photothermal Catalytic Reaction of Ethyl Acetate and NO Catalyzed by Biochar-Supported MnO_x-TiO₂Catalysts. Toxics. https://doi.org/10.3390/toxics12070478

In recent research, biochar-supported MnOx-TiO2 catalysts have shown promise for efficiently removing volatile organic compounds (VOCs) and nitrogen oxides (NO) simultaneously through a photothermal catalytic reaction. Traditionally, NH3-SCR is used for NO removal, and catalytic oxidation is employed for VOCs, but these methods often fall short in efficiency and can cause secondary pollution. By substituting ammonia with ethyl acetate (EA) in the reduction process, researchers aim to eliminate these issues.

Three types of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, derived from ginkgo shells, moso bamboo, and loofah, were created via pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More at 700°C and then loaded with MnOx and TiO2 through a hydrothermal process. Among these, the ginkgo shell-based catalyst (700-12-3GN) demonstrated the highest efficiency, converting 73.66% of NO and 62.09% of EA at 240°C with a catalyst loading of 300 mg. This superior performance is attributed to the higher concentration of active Mn4+ and Ti4+ species, excellent redox properties, and an optimal pore volume and size, rather than just a large specific surface area.

Characterization techniques such as XRD, BET, SEM, EDS, XPS, H2-TPR, and O2-TPD revealed that 700-12-3GN had the most favorable structural and chemical properties. The research highlights the importance of not just the biochar’s surface area but its pore volume and reactive species content for catalytic efficiency.

This study opens new avenues for using biochar in photothermal catalysis, offering a cost-effective, environmentally friendly approach for air pollution control, with potential applications in industrial settings where VOCs and NO are prevalent.