One outstanding research challenge in water-splitting electrocatalysis is that few known materials have both high catalytic activity and extended stability for the oxygen evolution reaction in acidic electrolytes, and these have primarily been limited to noble metal oxides. A rapid and scalable novel plasma synthesis technique has been employed to fabricate mixed metal oxide compositions of homogeneously phase-pure catalysts with an aim toward the development of acid-stable OER catalysts of low noble metal content. In particular, a composition of W_0.9Ir_0.1O_x has been characterized and shows high activity and stability at pH 0 following a standardized benchmarking protocol. A high-throughput plasma reactor nanoparticle printer has been developed to enable the rapid search for acid-stable OER catalysts with minimal to no platinum-group-metal elements. Such materials could improve the sustainability and economic competitiveness of proton exchange membrane electrolyzers.