Constructed with parallel or honeycomb channels micrometer to millimeter in diameter, monolithic catalysts and reactors have been utilized in various business sectors ranging from mechanical, automotive, fine chemicals, pharmaceutical, to biotechnology industries. However, the performance of state-of-the-art washcoating monolithic catalysts in industry suffers from some long-standing problems such as mediocre-uniformity, need for high catalyst loading, low materials utilization, random catalytic sites, poor washcoat adhesion, short life-time, degradation tendency, all of which lead to much compromised and less-than desirable catalytic performance. In this work, we significantly mitigated these issues and reduced precious metal and metal oxide usages by 10-40 folds, by directly integrating bare monolith structures with ultra-efficient, thermally stable, and physically and chemically well-defined nanostructure arrays. The welt-defined nanostructure array monolithic catalysts represent a new and effective model platform for bridging catalytic nanomaterials science and engineering with the practical industrial catalysis. (C) 2013 Elsevier Ltd. All rights reserved.