Standing waves in catalysis at single crystal surfaces

Recent experiments have demonstrated the existence of standing waves for the catalytic reaction CO+O→${\mathrm{CO}}_2$ on a Pt (110) surface. We study this reaction by adding spatial coupling terms to a kinetic reaction scheme originally proposed by Eiswirth, Krischer, and Ertl. We argue that the standing waves arise from a novel mechanism involving the parametric driving of finite-wave-vector waves via a globally oscillating reaction rate. This interaction is possible because of the (near) resonance of these two modes.