The controlled oxidation of hydrogen from an explosive mixture of gases using a microstructured reactor/heat exchanger and Pt/Al2O3 catalyst

With advances achieved in the area of microreactor technology, new possibil ities for the use of microchannel reactors in the field of heterogeneous ca talysis are now attainable. By exploiting these microstructured reactors fo r their relatively high surface-to-volume ratio and the inherent safety due to dimensions below the quenching distance at which explosions can propaga te, hazardous reaction mixtures can be handled safely. The aim of this pape r is to present the results on the catalytic H-2/O-2 reaction obtained from an alumina-coated microstructured reactor/heat exchanger that has been imp regnated with a platinum catalyst. With this reactor, explosive mixtures of gaseous hydrogen and oxygen (up to 50% by volume of H-2 in O-2) were safel y handled and the hydrogen was completely converted to water without explos ions by maintaining a heterogeneously catalyzed reaction. The homogeneous r eaction was prevented through efficient removal of the heat evolved from th is highly exothermic reaction with cooling gas flowing in the heat exchange r channels of the reactor. It is anticipated that the use of microstructure d reactors in catalysis research will add new levels of safety and control in studying chemical systems that necessarily involve explosive mixtures of gases. (C) 2000 Academic Press.