Boosting the electrocatalytic performance of Pt, Pd and Au embedded within mesoporous cobalt oxide for oxygen evolution reaction

Abstract

High efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) are essential components of renewable energy technologies. However, the high onset potential and limited active sites restrict the catalytic activity of current electrocatalysts. Therefore, we are motivated by the development of cheap and efficient catalytic electrodes to promote the sluggish water-splitting systems associated with the large-scale application of clean and renewable energy technologies. Herein, a novel, simple, and efficient routine is presented by noble metal particles embedded within mesoporous metal oxide materials as high-efficiency anode catalysts for OER. Highly ordered mesoporous Co3O4 was prepared by a nanocasting method using the silica KIT-6 as hard template, showing an enhanced electrochemical performance. Then, M - Co3O4 (M = Pt, Pd, Au) nanomaterials were prepared by a simple but novel chemical reduction method. They show the high surface area of 112.3, 81.0 and 73.6 m2 g−1, which can provide more active surface area exposure leads to shorter paths of charges from electrolyte to electrode surface. Moreover, a three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen, and can also keep catalyst nanoparticles in a well-dispersed condition with more active sites. Electrochemical measurements revealed that 20, 50, 25 wt% are the best weight contents for M (M = Pt, Pd, Au) in the Co3O4 with highest electrochemical activity (0.410, 0.415 and 0.422 V vs. SCE) and j0.7V reaching a maximum value. M-Co3O4(M = Pt, Pd, Au) materials exhibit superior activities and excellent long-duration stability in alkaline attributed to accelerating the formation of Co(IV) cations after being introduced M(M = Pt, Pd, Au) nanoparticles within mesoporous Co3O4. This kind of noble metal embedded within mesoporous oxide catalysts will hold a large potential as a highly promising electrocatalyst in the future.