Innovative Charge-Tuning\nfor Highly Dispersed Pt Catalysts:\nAchieving Deep CO Removal in Industrial H<sub>2</sub> Purification\nfor Fuel Cells

Proton exchange membrane fuel cells have strict requirements\nfor\nthe CO concentration in H<sub>2</sub>-rich fuel gas. Here, from the\nperspective of industrial practicability, a highly dispersed Pt catalyst\n(2–4 nm) supported on activated carbon (AC), which was modified\nby electronic promoters (K<sup>+</sup>) and structural promoters (isopropanol),\nis studied in detail. Compared with traditional metal oxide supports,\nthe K–Pt/AC catalysts, which benefit from the tuned charge\ndistribution, achieve a significant reduction of CO (from 1% to <0.1\nppb) under H<sub>2</sub>-rich conditions and show potential for used\nin large-scale industrial hydrogen purification. Experimental results\nand theoretical calculations reveal that the K atom, with its lower\nelectronegativity, contributes to the shift of surface Pt<sup>2+</sup> to a lower binding energy due to the presence of oxygen species\non the AC surface. This facilitates oxygen activation and accelerates\ndesorption of the CO<sub>2</sub> product, thereby accelerating the\nreaction process and enabling the deep removal of CO in a hydrogen-rich\natmosphere.