Fe-USY Zeolite Catalyst for Effective Decomposition of Nitrous Oxide

摘要

Zeolite matrix FAU is applied as an effective support that can be readily exchanged with ferric ions simply by wet ion exchange. The high exchange degree in this zeolite (USY) probably benefits from its larger channel dimension, which makes the diffusion of hydrated ferric ions into the channels easier. The as-prepared and subsequently calcined Fe-USY samples contain various kinds of iron species, which enable Fe-USY to efficiently decompose N_2O to N_2 and O_2. The presence of O_2 (20%), H_2O (2%), or both reduces the N_2O conversion only to a small extent at the same temperature. To test the feasibility and the catalytic activity in a practical situation, we prepared a monolithic Fe-USY/cordierite sample and investigated the N_2O conversion under similar conditions. Such a cordierite-supported Fe-USY catalyst (～9 wt % USY and 0.5 wt % Fe) shows the catalytic performance in N_2O decomposition similar to the pure Fe-USY catalyst. Remarkably, both the pure Fe-USY and Fe-USY/cordierite catalysts demonstrate a very good durability because there is no activity lost after 100 and 144 h tests. Thus, the Fe-USY zeolite shows its potential as a cost-effective catalyst for N_2O elimination in future applications.