Unconventional hcp/fcc Nickel Heteronanocrystal with Asymmetric Convex Sites Boosts Hydrogen Oxidation.

Developing non-platinum group metal catalysts for the sluggish hydrogen oxidation reaction (HOR) is critical for alkaline fuel cells. To date, Ni-based materials are the most promising candidates but still suffer from insufficient performance. Herein, we report an unconventional hcp/fcc Ni (u-hcp/fcc Ni) heteronanocrystal with multiple epitaxial hcp/fcc heterointerfaces and coherent twin boundaries, generating rugged surfaces with plenty of asymmetric convex sites.

CO-Tolerant Hydrogen Oxidation Electrocatalysts for Low-Temperature Hydrogen Fuel Cells.

The severe performance degradation of low-temperature hydrogen fuel cells upon exposure to trace amounts of carbon monoxide (CO) impurities in reformate hydrogen fuels is one of the challenges that hinders their commercialization. Despite significant efforts that have been made, the CO-tolerance performance of electrocatalysts for the hydrogen oxidation reaction (HOR) is still unsatisfactory. This Perspective discusses the path forward for the rational design of CO-tolerant HOR electrocatalysts.

Unconventional Bilateral Compressive Strained Ni-Ir Interface Synergistically Accelerates Alkaline Hydrogen Oxidation.

The alkaline hydrogen oxidation reaction (HOR) involves the coupling of adsorbed hydrogen (H) and hydroxyl (OH) species and is thus orders of magnitude slower than that in acid media. According to the Sabatier principle, developing electrocatalysts with appropriate binding energy for both intermediates is vital to accelerating the HOR though it is still challenging. Herein, we propose an unconventional bilateral compressive strained Ni-Ir interface (Ni-Ir()) as efficient synergistic HOR sites.