Reduction of the Pt loading required in cathodes is crucial for the development of passive direct methanol fuel cells (DMFCs). Herein, a novel membrane electrode assembly (MEA) that utilizes a MWCNT–Pt nanocomposite cathodic catalyst layer (CCL) with a 3D network structure is shown to require significantly less Pt loading. With a CCL Pt loading of 0.5 mg cm−2, the maximum power density of the prepared DMFC is 19.2 ± 0.4 mW cm−2 using 2.0 M methanol solution at 25 ± 1 °C, which is higher than that of the power density by a conventional MEA with twice the Pt loading (1.0 mg cm−2). Electrochemical tests show that the structure of the CCL decreases the charge transfer resistance of the cathode reaction and greatly increases the cathode catalyst utilization in comparison with the conventional MEA. The enhanced MEA performance is attributed to the discontinuous distributions of the Pt MWCNT structures and the formation of a cross-twined network within the CCL. This study could provide a promising way to reduce the cost of future commercialized DMFCs.

•ZnO nanorods are used as efficient sacrificial template to fabricate nano-network structure (NNS) within anode.•The DMFC with 50% reduced anode catalyst loading exhibits an enhanced performance.•The DMFC with NNS exhibits a significant increase in catalyst utilization and mass transfer efficiency.In this study, zinc oxide (ZnO) nanorods were used as efficient sacrificial template to fabricate nano-network structure (NNS) within anode catalyst layer (CL) and micro-porous layer (MPL) of a membrane electrode assembly (MEA). It resulted in a significant reduction of noble metal catalyst loading and enhancement of performance of a passive direct methanol fuel cell (DMFC). At a Pt–Ru loading of 1.0 mg cm−2, the MEA with NNS in anode CL exhibited a maximal power density of 28.4 mW cm−2 using 2 M methanol solution as fuel at 25 °C. However, for the conventional MEA with a Pt–Ru loading of 2.0 mg cm−2, the maximal power density was 29.0 mW cm−2. With the increase in Pt–Ru loading to 2.0 mg cm−2, the maximal power densities of the MEAs with NNS in anode CL and in both anode CL and MPL reached 38.6 and 40.2 mW cm−2, respectively. The improved performance of the MEAs with NNS was attributed to its property of higher catalyst utilization, higher mass transfer efficiency, and lower charge-transfer resistance compared to the conventional MEAs. However, the construction of NNS within both anode CL and MPL led to a relatively serious problem of cathode flooding, which restrained the further improvement in DMFC's performance. This study provided a perspective to fabricate novel pore structure to obtain high performance of passive DMFCs with low noble metal catalyst loading and low concentration methanol solution.