Benign by design. New catalysts for an environmentally conscious age

There is a pressing need for: (i) cleaner fuels (free of aromatics and of m inimal sulfur content) or ones that convert chemical energy directly to ele ctricity, silently and without production of noxious oxides and particulate s; (ii) chemical, petrochemical, and pharmaceutical processes that may be c onducted in a one-step, solvent-free manner, and that use air as the prefer red oxidant; and (iii) industrial processes that minimize consumption of en ergy, production of waste or the use of corrosive, explosive, volatile and nonbiodegradable materials. All these needs and other desiderata, such as t he in situ production and containment of aggressive and hazardous reagents, and the avoidance of use of ecologically harmful elements, may be achieved by designing the appropriate heterogeneous inorganic catalyst, which, idea lly should be cheap, readily preparable, and fully characterizable, prefera bly under in situ reaction conditions. A range of nanoporous and nanopartic le catalysts, designed, synthesized, characterized, and tested by the autho rs and their colleagues, that meet most of the stringent demands of sustain able development and responsible (clean) technology is described. Specific examples that are highlighted include: (a) the production of adipic acid (p recursor of polyamides and urethanes) without the use of concentrated nitri c acid or the production of greenhouse gases such as nitrous oxide; (b) the production of caprolactam (precursor of nylon) without the use of oleum. a nd hydroxylamine sulfate; and (c) the terminal oxyfunctionalization of line ar alkanes in air. The topic of biocatalysis and sustainable development is also briefly discussed, and a cautionary note is sounded concerning fast s creening methods for the discovery of new inorganic catalysts.