Engineered Sulfur-Resistant Catalyst System with an Assisted Regeneration Strategy for Lean-Burn Methane Combustion.

Catalytic combustion of methane, the main component of natural gas, is a challenge under lean-burn conditions and at low temperatures owing to sulfur poisoning of the Pd-rich catalyst. This paper introduces a more sulfur-resistant catalyst system that can be regenerated during operation. The developed catalyst system lowers the barrier that has restrained the use of liquefied natural gas as a fuel in energy production.

Promoter effect of BaO on CO oxidation on PdO surfaces.

The effect of bulk BaO promoter on CO oxidation activity of palladium oxide phase was studied by density functional calculations. A series of BaO(100) supported Pd(x)O(y) thin layer models were constructed, and energy profiles for CO oxidation on the films were calculated and compared with corresponding profiles for the most stable PdO bulk surfaces PdO(100) and PdO(101). The most stable of the thin films typically exhibit the same PdO(100) and PdO(101) surface planes; the PdO(100) dominates already with double layer thickness. The supporting promoter improves the CO oxidation activity of the Pd(x)O(y) phase via a direct electronic effect and introduced structural strain and corrugation. Changes in CO adsorption strength are reflected in oxidation energy barriers, and the promoting effect of even 0.3 eV can be seen locally. Easier oxygen vacancy formation may partially facilitate the reaction.