Fast Synthesis of Biochar by Hydrolysis with an Acid Catalyst for Efficient Low-Temperature SCR of NO

Biochar stands out as an excellent carrier for low-temperature SCR catalysts, but its synthesis is often time-consuming and requires high temperatures and fossil fuels. Therefore, sustainable and rapid synthesis methods are challenged. This paper proposes a sustainable method for the rapid synthesis of rice husk biochar by acid-catalyzed hydrolysis at ambient temperature and pressure. The results showed that the surface of the biochar synthesized by acid-catalyzed hydrolysis was smooth, and also the SiO₂ powder byproduct with uniform particle size was successfully obtained. Furthermore, a biochar carrier-based SCR catalyst was developed. The product demonstrated exceptional low-temperature denitrification performance with a denitrification efficiency of 96.8% at 180 °C. Notably, the product synthesis required a shorter time and exhibited higher denitrification efficiency and a wider temperature range than the biochar prepared by pyrolysis and chemical activation. Thus, acid-catalyzed hydrolysis proved to be a simple, low-energy, and sustainable method for producing high-quality biochar.