Manganese based materials for diesel exhaust SO2 traps

Study on the hydrothermal and SO2 stability of Al2O3-supported manganese and iron oxide catalysts for lean CO oxidation

“…This degree of deactivation is in line with investigations on Mn-based catalysts stated in the literature [50]. Although according to Tikhomirov et al [51] thermal decomposition of sulfated MnO x /CeO 2 in O 2 containing atmosphere is expected above 800 • C, lower temperatures of 750 • C were reported for Mn/Al 2 O 3 catalysts, especially for surface sulfates [52]. In the latter study, it was also suggested that the manganese sites are preferentially sulfated implying formation of MnSO 4 .…”

“…From this result, it is evident that the SO 2 aging is referred to the partial transformation of the active manganese oxide component to manganese sulfate. This deactivation process is also described in the literature [51,52]. The thermal treatment of the SO 2 -aged 20 Mn/Al 2 O 3 (FSP) and the resulting activity is assumed to evoke decomposition of the sulfate species, which is obviously possible due to the higher thermal stability of this catalyst.…”

“…The latter is supported also by the steep loose of activity after 2 h hydrothermal aging at 700 • C (Section 3.1). Alternatively, regeneration of Mn-based catalysts might be achieved by treatment with CO or H 2 at lower temperatures [50][51][52].…”

Powder and Monolith-Supported Sulphur Trap Materials Based on Modified Hydrotalcite-Derived Supports

“…octahedral molecular sieves (OMS) [22], mixed supported oxides, e.g. NaMn/Al 2 O 3 -CaO [16,18] or MnO x -CeO 2 mixed oxides [23].…”

Efeito da composição das correntes do conversor das unidades de FCC no desempenho catalítico de aditivos DESOx

“…Particularmente com relação aos processos de remoção de SO x , o uso de catalisadores baseados em óxidos de manganês tem sido investigado em trapas para captura de SO x da corrente de gases de exaustão de motores diesel ou a gasolina, com o objetivo de aumentar a vida útil dos catalisadores automotivos. 13,14 Por outro lado, no que concerne aos aditivos para catalisadores de FCC, o presente trabalho tem aspecto inovador, uma vez que não se encontra na literatura uma investigação sistemática do uso de aditivos contendo manganês.…”