An oxidation catalyst includes a support including particles of an alkaline earth salt, and first particles including a palladium compound on the support. The oxidation catalyst can also include precious metal group (PMG) metal particles in addition to the first particles intermixed together on the support. A gas permeable polymer that provides a continuous phase can completely encapsulate the particles and the support. The oxidation catalyst may be used as a gas sensor, where the first particles are chemochromic particles.
U.S. GOVERNMENT RIGHTS
 This invention was made with U.S. Government support under Florida Hydrogen Initiative contract #DEFC3604GO14225 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.