Highly selective ammonia oxidation to nitric oxide over supported Pt nanoparticles

Tailored Pt nanoparticles were prepared in strong alkaline ethylene glycol solution and deposited on α-Al2O3, γ-Al2O3, and CeO2–TiO2. The resulting supported catalytic materials were applied for ammonia oxidation between 473 and 1073 K in the temporal analysis of products reactor. Although the catalysts possessed only 0.005 wt.% Pt, they were active and selective for nitric oxide formation. The NO selectivity obtained over Pt/CeO2–TiO2 between 873 and 1073 K was around 98% and exceeded that of industrially relevant Pt wire. Both alumina-supported catalysts were less selective. Pt/CeO2–TiO2 also showed the highest NO selectivity in steady-state ambient pressure tests. The superior performance of Pt/CeO2–TiO2 is related to a synergy effect between the noble metal and the support since they provide adsorbed and lattice oxygen species for selective NH3 oxidation to NO in a complementary fashion.