Flame spray synthesis is investigated as a method for one-step synthesis and deposition of porous catalysts onto surfaces and into microreactors. Using a standard photolithographic lift-off process, catalysts can be deposited on flat surfaces in patterns with submillimeter feature sizes. With shadow masks, porous catalyst layers can be deposited selectively into microchannels. Using Au/TiO2 as test catalyst and CO oxidation as test reaction, it is found that the apparent activation energy of the deposited catalyst is similar to that normally seen for supported gold catalysts in the literature. The surface area of the deposited material is more than twice as large as when the flame-produced material is collected on a filter at the outlet of the flame reactor unit. (C) 2004 Elsevier Inc. All rights reserved.