Prominent Catalytic Activity Driven by Monatomic-Layered Uni-Sized Pt Clusters Directly Bound to Si Surface Originating from Strong Cluster-Substrate Interaction

Abstract

Preparation, catalytic activity and thermal stability of monatomic-layered uni-sized platinum cluster disks directly bound to a single-crystal Si surface are reviewed. The cluster disks were prepared by impact of uni-sized cluster ions onto the surface : cluster impact. Their catalytic activity in the CO oxidation was unveiled through surface-chemistry measurements ; the low-temperature catalytic activity and reaction sites involved in the CO oxidation were studied with temperature-programed desorption (TPD) measurements, and anti-poisoning ability against CO around room temperature was elucidated by measuring the turnover rate in gas-flow reactions under steady-state conditions. The thermal stability was evaluated by means of scanning-tunneling microscope (STM) with repetition of the sample heating. These specific properties of the cluster disks were explained according to electron accumulation at the sub-nano interface between the cluster disk and the substrate surface through strong chemical interaction between them.