低温液相法制备的纳米NiFe2O4上同时催化去除NOx和PM的特性

Simultaneous catalytic removal of NOx and soot over NiFe2O4 nano-particles synthesized by liquid catalytic phase transformation method at low temperature

通过液相催化相转化的方法制备出化学性质和晶相稳定的NiFe2O4纳米粒子，采用XRD、BET、TEM等手段对其进行表征；利用程序升温技术对其在同时催化去除柴油机尾气中氮氧化物和碳烟的反应进行了研究，并与高温固相法制备的NiFe2O4进行比较。结果表明，不同方法制备的NiFe2O4都能在紧接触时在富氧条件下使碳烟（PM）和氮氧化物（NOx）互为发生氧化还原反应生成CO2和N2，其中低温催化相制备的NiFe2O4纳米粒子具有更高的活性，在松接触条件下起燃温度为282℃，N2的最大转化率为14．1％。

NiFe2O4 nano-particles were synthesized with stabile chemical properties and crystalline phase by liquid catalytic phase transformation method at low temperature. The prepared nano-particles were characterized by XRD, BET and TEM. Simultaneous catalytic removal of NOx and soot over NiFe2O4 nano-particles was investigated in this paper by using temperature programmed reaction （TPR） and was compared with NiFe2O4 produced by solid reaction at high temperature. It turns out that NiFe2O4 produced by both methods could promote PM and NOx transferring to CO2 and N2 in tight-contact with soot, in which produced by liquid catalytic phase transformation method showed much better than the other one. The ignition temperature of soot was 282℃, and the maximum conversion of NOx to N2 was 14.1% on NiFe2O4 nano-particles in loose-contact.