The aging behavior of state-of-the-art SCR (selective catalytic reduction) catalysts, such as Cu-zeolites, Fe-zeolites, and VWT in the exhaust gases of H₂ and NH₃ combustion engines needs to be assessed. A particular challenge for the long-term stability of the SCR catalysts is the higher H₂O content of these types of exhaust gases referred to diesel and gasoline, which potentially leads to enhanced hydrothermal degradation and leaching. The project aims to elucidate the long-term stability as well as aging mechanisms of the current SCR catalyst technologies in the context of combustion engines fed by these sustainable fuels. The catalysts are taken from commercial monoliths and are investigated in the form of 1’’x 2’’ cores. The gas compositions during the aging procedure are related to the specific contents of H₂O and O₂ of the H₂ and NH₃ combustion engines. The aging procedure is carried out at relevant temperatures and for different times on stream. After each aging step, the mini-monoliths are tested toward standard and fast-SCR activity using realistic model exhaust gas. Extensive physical-chemical characterization of catalysts from laboratory is performed, plus special investigations for catalysts aged at the engine test bench. As output of the project, boundary conditions for the long-term performance of the actual SCR catalyst technologies to meet emission targets are defined, and counterstrategies regarding catalyst formulations are suggested.

Back to the funding projects