Reaction gas treatment promoting activity and stability of PdO for lean methane oxidation over phosphorus modified Pd/Al2O3 catalysts

Comparative Investigation of Three-Way Conversion over Palladium-Based Catalysts Supported on Phosphorus-Doped and Phosphorus-Free Ceria–Zirconia–Alumina

“…The consumption peak at 129 °C is related to the reduction of oxygen species adjacent to Pd sites. , The peaks at 171, 244, and 293 °C are attributed to the reduction of surface lattice oxygen. , The addition of phosphorus causes the consumption peak to shift to a higher temperature, indicating a decline of reducibility, which leads to a weaker metal–support interaction. The broad peak above 350 °C comes from the reduction of other forms of surface oxygen. , As summarized in Table , the total H 2 uptake of Pd/CZPA is greater than that of Pd/CZA, which means that the addition of P promotes the formation of oxygen, especially lattice oxygen.…”

“…The broad peak above 350 °C comes from the reduction of other forms of surface oxygen. 31,34 As summarized in Table 6, the total H 2 uptake of Pd/CZPA is greater than that of Pd/CZA, which means that the addition of P promotes the formation of oxygen, especially lattice oxygen.…”

“…Such an interaction helps to suppress the phase transformation and grain growth of alumina and significantly improve the CO oxidation activity of the aged catalyst. Yan et al 34 studied the effect of reaction gas treatment on the performance of P-modified Pd/Al 2 O 3 catalyst for dry/wet methane oxidation. It was found that the uniform and stable P species in Al 2 O 3 enhanced the metal−support interaction and the availability of oxygen in the support.…”

What about the development of catalytic after-treatment processes as part of the transition from vehicles powered by liquid fuels to gaseous fuels

“…Under stoichiometric or slight rich conditions, oxygen depletion slows the kinetics and alters the stability of PdO decomposing more easily into less active Pd metal. 38 The fast autothermal sintering is also an important issue particularly in the presence of steam in the exhaust. 39 Presently, the strategies envisioned to suppress the related detrimental effects due to PdO decomposition and particle sintering are quite unclear.…”