A new reaction channel in H(g)+D(a)/Pd(100): absorption versus abstraction

A study on the interaction of gas-phase atomic H(g) with D(a) atom chemisor bed on Pd(100) surface is presented. We found a new elementary reaction pro cess: a H(g) atom at 1800 K impinging on the D(a)-saturated Pd(100) surface at 105 K forces a preadsorbed D(a) atom to be absorbed into a bulk site. N either direct absorption of H(g) nor abstraction was observed, which were r eported to occur at Ni surfaces. The mechanism of the absorption is discuss ed, and the "stamping" model is proposed. A marked difference in the reacti on selectivity with the case for Ni surface previously reported is discusse d in terms of the potential energy surface. (C) 1999 Elsevier Science B.V. All rights reserved.