The Electrocatalysis of Oxygen Reduction on Platinum and Its Alloys

The high cost and poor durability are the pressing issues that need to be addressed before pushing the polymer electrolyte membrane fuel cells (PEMFCs) to the market. The primary effort is made on the electrocatalysis by lowering the loading of Pt-group which are scarce and expensive but remain as the most efficient material until now. State-of-the-art Pt and Pt-based electrocatalysts usually offer an exceptional electrocatalytic activity as well as durability toward the oxygen reduction reaction (ORR), but the trick lies in their well-controlled surface structure and composition. Theoretical discussion based on the first principle about the cathodic ORR in this chapter will provide new insights into material choice, surface element distribution and the closed crystallographic orientation designs for electrocatalysts. Therein, alloying Pt with 3d transition metals, Pt shells and {111}-facets are regarded as excellent characteristics for improving the ORR performance. The experimental strategies including chemical routes, electrodeposition and thermal annealing for achieving those well-designed structures are then concluded. Besides, we also shed light on the hinder for practical application of those electrocatalysts in the PEMFCs.