The synergistic effect of phosphotungstic acid as catalyst and Cu-based metal-organic framework in dry desulfurization enhances the ability to capture SO2：Synergistic effect of catalytic action and CO2 selectivity performance

Currently, the desulfurization agents employed in dry desulfurization technology face challenges such as slow reaction rates and low desulfurization efficiency. This study integrates phosphotungstic acid(HPW) into Cu-based Metal-organic framework(Cu-MOFs) using a hydrothermal synthesis method, enhancing the performance of the desulfurization agent through a combination of catalytic oxidation and adsorption. Experimental results indicate that optimal desulfurization effects are achieved when the ratio of Copper nitrate trihydrate (Cu(NO 3 ) 2 ) to 1, 3-phenyltrifamilic acid (H 3 BTC) is 2:1, with an HPW addition of 1.2 wt%, and a hydrothermal synthesis duration of 24 hours. In a fixed bed desulfurization system, HPW-2@Cu-MOF demonstrates the best performance at a reaction temperature of 200℃, achieving a sulfur dioxide removal efficiency nearing 100 %, a specific surface area of 612.20 m 2 /g, a pore volume of 0.2568 cm 3 /g, and a sulfur capacity of 90.464 mg/g. The incorporation of HPW facilitates the conversion of sulfur dioxide (SO 2 ) to sulfur trioxide (SO 3 ) under the influence of surface oxygen (O α , O β ), resulting in a 10.52 % increase in SO 3 content compared with Cu-MOFs. When the flue gas contains a certain concentration of carbon dioxide, HPW-2@Cu-MOF preferentially reacts with SO 2 due to the adsorption between Cu 2+ and SO 2 . X-ray photoelectron spectroscopy (XPS) characterization reveal that W 5+ serves as the active center in HPW, the content of W 5+ in HPW-2@Cu-MOF was higher than others, accounting for 90.6 %. Thermo Gravimetric Analysis clearly demonstrates that the thermal stability of Cu-MOFs loaded with HPW has been significantly enhanced.