Direct methanol fuel cells are attractive power conversion devices for portable and stationary applications. Many electrocatalysts have been explored for fuel cell applications but there is scope to design newer and more efficient electrocatalytic materials. For this purpose we have synthesized Mo₂C and bimetallic NbC‐Mo₂C carbide phases by carbothermic reduction process. The carbide catalysts are characterized by various analytical techniques. The carbide samples are higly porous and their surface areas are of the order of 630 m² g⁻¹. Usually Pt is the state‐of‐the‐art anode catalyst in direct methanol fuel cells. Here, Nb‐Mo₂C and 10 wt% Pt nanoparticles are deposited on reduced graphene oxide support to obtain Pt/Nb‐Mo₂C‐rGO. This material shows highest mass activity of 836.4 mA mg_Pt⁻¹ when compared to 10 wt% Pt/Mo₂C‐rGO and bare 20 wt% Pt/rGO catalysts. Notably, electrochemical tests show that the 10 wt% Pt/Nb‐Mo₂C‐rGO catalyst exhibits lower onset potential, large electrochemical surface area, higher activity, and stability for methanol electro‐oxidation in acidic solution compared to the Pt/Mo₂C‐rGO and Pt/rGO catalysts. The activty enhancement is atributed to the defective nature of the interface between Pt, Nb‐Mo₂C and rGO. It is found that Nb‐Mo₂C not only alleviates CO poisoning of Pt nanoparticles, but also generates oxygen containing species at lower potentials. This process helps scavenging the intermediate species such as CO_ads on Pt surfaces and regenerates the active Pt sites for routine alcohol oxidation reaction. The chronopotentiometry and chronoamperometry studies also show that Pt/Nb‐Mo₂C‐rGO exhibits lower alcohol oxidation overpotential and longer polarization time/stability compared to Pt/Mo₂C‐rGO and bare Pt/rGO catalysts.

中文翻译：

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NbC / Mo2C相促进的Pt / rGO电催化剂的增强的甲醇电氧化活性

直接甲醇燃料电池是便携式和固定式应用的有吸引力的功率转换设备。已经探索了许多用于燃料电池应用的电催化剂，但是仍有设计新的和更有效的电催化材料的空间。为此，我们通过碳热还原法合成了Mo ₂ C和NbC-Mo ₂ C双金属碳化物相。碳化物催化剂的特征在于各种分析技术。碳化物样品是多孔的，其表面积约为630 m ²  g ^-1。通常，Pt是直接甲醇燃料电池中最先进的阳极催化剂。在这里Nb-Mo ₂将C和10 wt％的Pt纳米颗粒沉积在还原的氧化石墨烯载体上以获得Pt / Nb-Mo ₂ C-rGO。与10 wt％的Pt / Mo ₂ C-rGO和裸露的20 wt％的Pt / rGO催化剂相比，该材料的最高质量活度为836.4 mA mg _Pt ^-1。值得注意的是，电化学测试表明，10％（重量）的Pt / Nb系沫₂ C-RGO催化剂表现出比的Pt /沫降低开始电位，大的电化学表面面积，更高的活性，和对在酸性溶液中的甲醇的电氧化稳定性₂ C‐rGO和Pt / rGO催化剂。活性增强归因于Pt，Nb-Mo ₂ C和rGO之间的界面缺陷。发现Nb-Mo ₂C不仅减轻了Pt纳米颗粒的CO中毒，而且还以较低的电位生成了含氧物质。此过程有助于清除中间物种，例如Pt表面上的CO_广告，并再生用于常规醇氧化反应的活性Pt位点。计时电位法和计时电流法研究还显示，与Pt / Mo ₂ C-rGO和裸露的Pt / rGO催化剂相比，Pt / Nb-Mo ₂ C-rGO表现出更低的醇氧化超电势和更长的极化时间/稳定性。