A PERSPECTIVE ON NANOCLUSTER CATALYSIS - POLYOXOANION AND (N-C4H9N-TO-300) NANOCLUSTER SOLUBLE HETEROGENEOUS CATALYSTS( STABILIZED IR(O) (SIMILAR)

Following a review of the background terms, definitions and key litera ture necessary to understand the rapidly developing and promising area of nanocluster catalysis, the recent report of polyoxoanion-stabilize d Ir(0)(similar to 190-450) (hereafter Ir(0)(similar to 300)) nanoclus ter catalysts is reviewed. Specifically, the experimental observations relating to three principle questions concerning these soluble-oxide- supported, Ir(0)(similar to 300) nanocluster catalysts are reviewed: ( i) their catalytic activity (in a prototypical structure-insensitive r eaction, cyclohexene hydrogenation); (ii) their lifetime; and (iii) th eir thermal stability, each in direct comparison to three established heterogeneous Ir(0) catalysts [7.9% dispersed 1% Ir(0)/gamma-Al2O3, Ex xon's 80% dispersed 1% Ir/eta-Al2O3, and a low surface area Ir(0) prec ipitate]. In addition, observations of W-VI to W-V. reduction of the p olyoxoanion by Ir(0)(similar to 300) and H-2 are summarized, results w hich provide the first soluble-oxide version of the well known spillov er of hydrogen in heterogeneous catalysis.