Pt-based nanoparticles decorated by phosphorus-doped CuWO4 to enhance methanol oxidation activity

Abstract

Direct methanol fuel cells are high-efficiency power storage equipment, while for methanol oxidation reaction, weak catalysis and carbon monoxide poisoning make them unsuitable for wide commercialization. In this study, we synthesized a phosphorus-doped CuWO₄ carbon nanocomposite as a Pt-based co-catalyst (Pt–C/P–CuWO₄) by hydrothermal, low-temperature phosphating and NaBH₄ reduction methods. The nanocomposite has enriched surface area and active sites of Pt–C/P–CuWO₄, and the involved electrochemical tests have indicated that Pt–C/P–CuWO₄ exhibits excellent catalytic activity (1422 mA mg_Pt⁻¹) towards methanol oxidation in an acid solution, exhibiting 1.43, 1.50 and 4.17 times better catalytic activity than Pt/C–CuWO₄ (994 mA mg_Pt⁻¹), Pt–C/P–CuO (920 mA mg_Pt⁻¹), and Pt/C–H (341 mA mg_Pt⁻¹), respectively. Noticeably, the Pt–C/P–CuWO₄ catalyst demonstrates optimal tolerance in anti-poisoning, and has an initial potential of 0.15 V lower than that of Pt/C–H. This excellent catalytic activity can be imputable to the doping of phosphorus, which enhanced the conductivity and regulated the electronic structure of the bimetallic oxide, thus enhancing the interactions between the carrier and Pt, and is conducive to the formation of small-sized Pt nanoparticles. Therefore, the construction of phosphorus-doped CuWO₄ carbon nanocomposites may provide an alternative approach to the exploitation of other excellent electrocatalysts.