Electrochemical adsorption behaviour of platinum stepped surfaces in sulphuric acid solutions

Abstract In this paper a new technique for the orientation, cutting and polishing of small platinum single-crystal planes is given whose angular accuracy is within 3 min. This is required for the preparation of stepped surfaces with a well-controlled step density. Pt (511), (310), (211) and (331) surfaces, otherwise noted 3 (100)×(111), 3 (100)×(100), 3 (111)×(100) and 3 (111)×(111), have been prepared and their electrosorption properties studied. The results show that electrochemically adsorbed hydrogen is a sensitive probe to steps and terraces sites which may be characterised by voltammetry. The use of samples with narrow terraces containing three rows of atoms allows the possibility to correlate the absence of the most stongly bonded hydrogen state to the absence of bidimensional long-range order both on (100) and (111) terraces.