Exploring the Synthesis of Mesoporous In/H-β-NC Catalysts by Desilication Using CTAB Combined with NaOH and Its Application in CH₄-SCR of NO

Mesoporous In/H-β-NC catalysts were synthesized by desilication through introducing low-cost cetyltrimethylammonium bromide (CTAB) and NaOH as etching agents. The mesoporous In/H-β-NC catalysts prepared by adding surfactant CTAB could effectively improve the denitration performance. Synthesis conditions were optimized by different volumes of NaOH and etching times. Mesoporous In/H-β-NC catalysts prepared with 6 mL of NaOH (0.4 M) and 6 h of etching time showed the highest NO_x conversion in the presence of sulfur and water. Also, the denitration efficiency reached 50.3% at 650 °C. It was clear that the mesoporous structure could expose more surface InO⁺ active sites and surface reactive oxygen species, which enhanced the adsorption of NO and improved the sulfur and water resistance of the catalysts. Besides, the possibility of the practical application of In/H-β-NC catalysts in a CH₄-SCR system was explored. The experimental results exhibited that the catalytic performance of the In/H-β-NC catalyst could reach 91% with the space velocity of 10 000 h^-1, CH₄/NO molar ratio of 1.5:1, SO₂ concentration of 50 ppm, and water content of 5%.