Electronic structure and reactivity of La1-xSrxCo1-yCuyO3 and La2-xSrxCo1-yCuyO4

SR VUV photoemission is used to explore the surface reactivity of La1-xSrxC o1-yCuyO3 and La2-xSrxCo1-yCuyO4 in aqueous solution. This is combined with studies of activity in peroxide decomposition in order to assess the usefu lness of the materials as aqueous oxidation catalysts. Both surface reactiv ity to water, and activity in peroxide decomposition decrease with increasi ng Cu content, suggesting that the Cu-rich A(2)BO(4) layered perovskites ar e more suitable potential catalyst materials than the Co-rich ABO(3) perovs kites. Changes in reactivity are discussed in terms of the transition metal d electron count. (C) 1999 Elsevier Science B.V. All rights reserved.