Selective exposure of active surfaces of Pt-based electrocatalysts has been demonstrated as an effective strategy to improve Pt utilization and promote oxygen reduction reaction (ORR) activity in fuel cell application. However, challenges remain in stabilizing those active surface structures, which often suffer undesirable degradation and poor durability along with surface passivation, metal dissolution, and agglomeration of Pt-based electrocatalysts. To overcome the aforementioned obstacles, we here demonstrate the unique (100) surface configuration enabling active and stable ORR performance for bimetallic PtCo nanodendrite structures.
View Article and Find Full Text PDFWe have studied the reforming reaction of ethanol co-adsorbed with atomic oxygen (O*, * denotes adspecies) and deuterated water (DO*) on a Rh(111) surface, with varied surface probe techniques under UHV conditions and with density-functional-theory calculations. Adsorbed ethanol molecules were found to penetrate readily through pre-adsorbed water, even up to eight overlayers, to react at the Rh surface; they decomposed at a probability promoted by the water overlayers. The production probabilities of H, CO, CHCH and CH continued to increase with co-adsorbed DO*, up to two DO overlayers, despite separate increasing rates; above two DO overlayers, those of H, CO and CHCH were approximately saturated while that of CH decreased.
View Article and Find Full Text PDFPt-oxygen-containing species (Pt-OCS) catalysts, in which OCS (e.g., metal-oxides) are decorated on a Pt surface, possess enhanced ethanol oxidation reaction (EOR) activity and stability compared with pure Pt and are promising in practical applications of direct ethanol fuel cells.
View Article and Find Full Text PDF