Rational Design of NiZn_x@CuO Nanoarray Architectures for Electrocatalytic Oxidation of Methanol

Abstract

Methanol oxidation reaction (MOR) in anodes is one of the significant aspects of direct methanol fuel cells (DMFCs), which also plays a critical role in achieving a carbon-neutral economy. Designing and developing efficient, cost-effective, and durable non-Pt group metal-based methanol oxidation catalysts are highly desired, but a gap still remains. Herein, we report well-defined hierarchical NiZn x @CuO nanoarray architectures as active electrocatalysts for MOR, synthesized by combining thermal oxidation treatment and magnetron sputtering deposition through a brass mesh precursor. After systematically evaluating the electrocatalytic performance of NiZn x @CuO nanoarray catalysts with different preparation conditions, we found that the NiZn1000@CuO (thermally oxidized at 500 °C for 2 h, nominal thickness of the NiZn alloy film is 1000 nm) electrode delivers a high current density of 449.3 mA cm–2 at 0.8 V for MOR in alkaline media as well as excellent operation stability (92% retention after 12 h). These outstanding MOR performances can be attributed to the hierarchical well-defined structure that can not only render abundant active sites and a synergistic effect to enhance the electrocatalytic activity but also can effectively facilitate mass and electron transport. More importantly, we found that partial Zn atoms could leach from the NiZn alloy, resulting in rough surface nanorods, which would further increase the specific surface area. These results indicate that the NiZn1000@CuO nanoarray architecture could be a promising Pt group metal alternative as an efficient, cost-effective, and durable anode catalyst for DMFCs.

Highly electron-deficient ultrathin Co nanosheets supported on mesoporous Cr2O3 for catalytic hydrogen evolution from ammonia borane

“…2c). [45][46][47] The presence of Co δ+ species is attributed to the electron transfer between Co nanosheets and mesoporous Cr 2 O 3 and inevitable oxidation in the sample preparation process. The above results indicated the formation of the Co-O-Cr bond in Co/Cr 2 O 3 , which is beneficial for electron transfer under light irradiation.…”

Milestones of Electrocatalyst Development for Direct Alcohol Fuel Cells

“…Oxygen electro-reduction reaction (ORR) is not only a vital half-reaction for fuel cell systems, but it is also relevant for NiZn 1000 @CuO MOR 1.0 m KOH + 0.5 m CH 3 OH 449.3 mA cm −2 (current density) 92% (after 12 h CA) [136] NiCo/N-CNFs@800 MOR 1.0 m KOH + 1.0 m CH 3 OH 124.7 mA cm −2 (current density) 61.8% (after 1000 CVs) [124] CoNi@NC/NCNTs-400 MOR 0.…”

Revisiting the Roles of Carbon in the Catalysis of Lithium–Sulfur Batteries

“…The ultrathin carbon shell is significant to balance stability and activity, but this consideration is often overlooked in many reports. [39] Therefore, we will emphasize the effect of different characteristics of carbon supports on the interaction between carbon and catalyst, as well as their influence on the catalytic activity of LSBs (Figure 1).…”