In this work, glucose acted as green and mild reductant, transition metal ions (Mn²⁺, Ni²⁺, Co²⁺) are controllably reduced via hydrothermal reduction and pyrolysis. Composite particles composed of transition metals and their oxides (TM@TM_xO_y) are effectively modified on the reduced graphene oxide (rGO) in the above process. Glucose can be effectively utilized to control the reduction of different transition metal ions so as to obtain the optimal TM@TM_xO_y-rGO support. It is very advantageous for uniformly loading the small-sized palladium nanoparticles (NPs) and enhancing the electrocatalytic performance. The results indicate that Pd/Mn@Mn₃O₄-rGO catalyst achieves the highest catalytic activity, which is 6.28 times as the commercial Pd/C catalyst (JM). It could be due to well-dispersed Pd NPs with small size (~ 2.53 nm) and support-metal synergistic interaction (SMSI) between TM@TM_xO_y-rGO support and Pd NPs. It is very potential for Pd/Mn@Mn₃O₄-rGO catalyst to improve electrocatalytic performance of direct methanol fuel cells in the future.

在这项工作中，葡萄糖作为绿色温和的还原剂，通过水热还原和热解可控制地还原过渡金属离子（Mn ²⁺、Ni ²⁺、Co ²⁺）。在上述过程中，由过渡金属及其氧化物（TM@TM _x O _y）组成的复合颗粒在还原氧化石墨烯（rGO）上得到了有效的改性。可以有效地利用葡萄糖来控制不同过渡金属离子的还原，从而获得最佳的 TM@TM _x O _y -rGO 载体。这对于均匀负载小尺寸钯纳米粒子（NPs）和提高电催化性能非常有利。结果表明，Pd/Mn@Mn ₃O ₄ -rGO 催化剂的催化活性最高，是商用 Pd/C 催化剂（JM）的 6.28 倍。这可能是由于小尺寸（~2.53 nm）的分散良好的 Pd NP 以及 TM@TM _x O _y -rGO 载体和 Pd NP之间的载体-金属协同相互作用（SMSI）。Pd/Mn@Mn ₃ O ₄ -rGO催化剂在未来提高直接甲醇燃料电池的电催化性能方面具有很大的潜力。