Me-ZSM-5 monolith foams for the NH3-SCR of NO

Self-supported ZSM-5 zeolite monolith foams (ZMFs) with different Si/Al ratios have been successfully prepared by hydrothermal synthesis with a polyurethane foam (PUF) template followed by calcination in air at 550 °C to harden. Cu or Mn have been introduced on preformed ZMF samples to obtain monolithic catalysts that have been fully characterized by morphological (XRD and SEM), textural (BET and pore size distribution), mechanical (compressive strength) and chemical (ICP-MS) analyses, and eventually tested in the Selective Catalytic Reduction of NO with NH3 in the temperature range 100-450 °C. The zeolite monolith foams are characterized by a well crystallized ZSM-5 structure, a BET surface area ca. 420 m2 g−1 and remarkable mechanical resistance even without any binder. Those structured catalysts show specific catalytic activity in line with powdered counterparts, but they can guarantee improved NO conversion due to the higher amount of catalyst per unit volume of reactor and to their superior mass transfer coefficients coupled to low internal diffusion limitations.