The development of microreactors for the catalytic reforming of fuels, such as methanol and hydrocarbons, for on-site H2 production has grown rapidly in the past few years. Highly porous inverted beaded catalyst support structures made from silicon carbide (SiC) and silicon carbonitride (SiCN) are fabricated, and have integrated these structures within high-density, non-porous alumina housings. The integrated ceramic microreactors exhibited excellent thermal and chemical stability up to 1200°C in air, and the SiC or SiCN support structures have geometric surface areas between 105 and 108 sq m/cu m. These catalyst support structures have a void fraction of 0.74, significantly reducing the pressure drop compared to packed catalytic beds. The channeling of reactants occurring with packed particles is avoided by the use of these inverted beaded porous monoliths. Efforts in the fabrication and characterization of the SiC and SiCN porous structures, and their integration into alumina reactor housings are described. The conversion data for these integrated ceramic microreactors at up to 1000°C for the decomposition of ammonia and the steam reforming of propane at temperatures above 800°C are presented. This is an abstract of paper presented at the AIChE Spring National Meeting (Orlando, FL 4/24-26/2006).