Abstract Interconnected nanoparticle-stacked two-dimensional Pt and porous PtNi alloy nanosheets are synthesized via galvanic replacement of Ni nanobelts. The Pt and porous PtNi nanosheets achieve a factor of approximately 1.3 and 2.3 enhancement in mass activity at 0.9 V versus RHE for oxygen reduction reaction relative to commercial Pt black, respectively. The practicability of Pt and porous PtNi nanosheets used as cathodic electrocatalysts for passive direct methanol fuel cells (DMFCs) is investigated. The passive DMFCs with Pt nanosheets (1.0 mg(Pt) cm−2) and porous PtNi nanosheets (0.8 mg(Pt) cm−2) exhibit excellent performance with satisfactory stability at 25 °C, which is slightly higher than that of the conventional cell with 2.0 mg(Pt) cm−2. The performance improvement of cells with Pt and porous PtNi nanosheets is attributed to the enhanced electrocatalytic activity and decreased charge transfer resistance of the cathodic catalyst layer. Benefiting from the porous structure of the PtNi nanosheets, the cell's performance is further boosted due to an increased Pt utilization. This work may provide an applicable approach to develop two-dimensional electrocatalysts for passive DMFCs, revealing a new strategy to decrease the usage of platinum.

中文翻译：

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互连纳米颗粒堆叠的铂基纳米片作为被动直接甲醇燃料电池的活性阴极电催化剂

摘要 通过 Ni 纳米带的电流置换合成了相互连接的纳米粒子堆叠二维 Pt 和多孔 PtNi 合金纳米片。相对于商业 Pt 黑，Pt 和多孔 PtNi 纳米片在 0.9 V 与 RHE 下的氧还原反应的质量活性分别提高了大约 1.3 和 2.3 倍。研究了 Pt 和多孔 PtNi 纳米片用作被动直接甲醇燃料电池 (DMFC) 阴极电催化剂的实用性。具有 Pt 纳米片 (1.0 mg(Pt) cm−2) 和多孔 PtNi 纳米片 (0.8 mg(Pt) cm−2) 的被动 DMFC 在 25 °C 下表现出优异的性能和令人满意的稳定性，略高于传统的2.0 mg(Pt) cm−2 的电池。具有 Pt 和多孔 PtNi 纳米片的电池的性能改进归因于增强的电催化活性和降低的阴极催化剂层的电荷转移电阻。受益于 PtNi 纳米片的多孔结构，由于 Pt 利用率的提高，电池的性能得到进一步提升。这项工作可能为开发用于无源 DMFC 的二维电催化剂提供了一种适用的方法，揭示了一种减少铂使用的新策略。