Bimetallic Ni–Cr nano-oxide catalysts were synthesized by thermal decomposition method and were investigated as the anode electrocatalysts for the oxidation of methanol. The catalysts were characterized by X-ray diffraction and transmission electron microscopy. The electroactivity of the catalysts towards methanol oxidation in a solution containing 0.25 M NaOH and 1.0 M MeOH was examined using cyclic voltammetry and chronoamperometry. The results indicate that a mixture of rhombohedral-structured NiO and Cr2O3 nanocrystals generated at the calcination temperature of 500–700 °C while octahedral-structured spinel NiCr2O4 formed at higher temperature. The influence of metallic molar ratio on the electrocatalytic performance of the catalysts was studied. The Ni–Cr nano-oxides prepared at comparatively low temperature displayed significantly higher catalytic activity and durability in alkaline solution toward electrooxidation of methanol compared with the pure nano NiO. The results indicate a synergy effect between NiO and Cr2O3 enhancing the electrocatalytic properties of the bimetallic Ni–Cr nano-oxide catalysts. Meanwhile, NiCr2O4 hardly increased the activity and durability of the catalyst. In addition, the Ni–Cr catalyst also exhibited excellent stability and good reproducibility. Therefore, Ni–Cr nano-oxide catalyst may be a suitable and cheap electrocatalyst for methanol oxidation in alkaline medium.
双
金属Ni–Cr纳米氧化物催化剂通过热分解法合成,并作为
甲醇氧化反应的阳极电催化剂进行了研究。催化剂通过X射线衍射和透射电子显微镜进行表征。使用循环伏安法和计时安培法考察了催化剂在含有0.25 M NaOH和1.0 M MeOH溶液中的
甲醇氧化电活性。结果表明,在500–700 °C的煅烧温度下生成了菱方结构的NiO和
Cr2O3纳米晶体,而在更高温度下形成了八面体结构的尖晶石NiCr2O4。研究了
金属摩尔比对催化剂电催化性能的影响。相比于纯纳米NiO,在相对低温下制备的Ni–Cr纳米氧化物在碱性溶液中对
甲醇电氧化反应表现出显著更高的催化活性和耐久性。结果显示NiO和 之间存在协同效应,提高了双
金属Ni–Cr纳米氧化物催化剂的电催化性能。同时,NiCr2O4几乎没有提高催化剂的活性和耐久性。此外,Ni–Cr催化剂还表现出优良的稳定性和良好的重现性。因此,Ni–Cr纳米氧化物催化剂可能是
甲醇在碱性介质中氧化的适宜且廉价的电催化剂。