Direct observation of electrocatalytic synergy

Here we describe an approach that directly and unambiguously establishes the synergistic effect between surfaces when brought into close proximity (angstrom's regime) through the use of a scanning tunneling microscope. As a model system, we have employed the electrocatalytic oxidation of CO chemisorbed onto a Pt(111) single-crystal electrode upon engaging a Ru tip. Not only have we been able to observe clear and compelling evidence of a synergistic effect, but also, this approach provides valuable mechanistic details not accessible from conventional measurements.