Ab Initio Study of Doped Tin Niobates and Tantalates as Prospective Catalyst Supports for Water Electrolysis

Abstract

The electronic structure of Sn2Ta2O7, Sn2Nb2O7, SnTa2O6, and SnNb2O6 compounds doped with small amounts of As, Sb, Bi, Cr, Mo, and W has been calculated in an attempt to identify new electrochemically stable viable catalyst supports for water electrolysis. Vienna ab-initio simulation package (VASP), within the projector augmented-wave (PAW) method in the general gradient approximation (GGA) for conducting the exchange-correlation corrections, has been utilized for the calculations. The role of doping 5A- and 6B-elements in improving the electronic conductivity has been discussed. Discussion of the cohesive energies for the materials and their electronic conductivity indicates that the thoreaulite structure of SnTa2O6 doped with As, Sb, or Bi could be the most appropriate candidates for use as catalyst supports in water electrolysis.