Nanofibrous SUZ-4 loading Pt used for selective catalytic reduction of NOx by hydrogen

• Nanofibrous SUZ-4 zeolite is firstly used as catalyst support.
• The nanofibrous SUZ-4 is characterized to be along its 6-, 10-ring channels.
• The nanofibrous HSUZ-4 loading Pt is much more active than Pt/HZSM-5 for H2-SCR.
• The activity of Pt/HSUZ-4 catalyst is well associated with the HSUZ-4 morphology.
• A characterization method for identifying Pt ions in the SUZ-4 channel is proposed.

Nanofibrous SUZ-4 zeolite (NF) was synthesized for preparing the Pt/HSUZ-4 catalyst used in the selective catalytic reduction of NOx by hydrogen (H2-SCR). The seed dissolution during the crystallization played an important role for the nanofibrous SUZ-4 formation. It was found that the zeolite NF is oriented along the 10-ring channels, and it has much more Brönsted acid sites on its external surface compared with general SUZ-4 zeolite. Consequently, Pt primarily existed as the well-dispersed particles (∼5 nm) on the NF external surface for the Pt/NF catalyst prepared by impregnation. In comparison with 0.1 wt.% Pt/HZSM-5 as well as general 0.1 wt.% Pt/HSUZ-4, the 0.1 wt.% Pt/NF catalyst gave much higher activity and N2 selectivity in the H2-SCR. For identifying the Pt ions in SUZ-4 zeolite channels, the band at 1652 cm−1 ascribed to nitrous species adsorbed on the ions was proposed.

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