半焦负载Na-Fe催化还原NO的研究

在石英固定床反应器上于常压下研究了煤焦负载Na或Fe催化还原NO的反应，同时研究了Na-Fe复合催化剂的催化特性。研究结果表明：Na或Fe催化剂的催化行为差异较大，低温下Na的催化活性高于相同负载量的Fe，而温度较高时，二者的催化活性顺序与低温时相反。Na的催化活性随负载量的增加而迅速增大，而Fe的催化活性随温度的升高增加迅速。在保持相同的负载量下，一定配比的Na－Fe复合催化剂的催化活性高于其中任何单一催化剂的催化活性。在不加其他还原剂的条件下，负载于煤焦上的Na-Fe复合催化剂可有效地催化还原NO，得到了高的还原转化率。复合催化剂高的催化活性预示Na-Fe在制备过程中的相互作用以及催化半焦还原NO的反应中具有协同作用。

REDUCTION OF NO OVER COAL CHARS LOADED WITH Na-Fe CATALYSTS

The decomposition of NO over coal chars loaded with Na and Fe catalysts was investigated in a quartz fixed bed reactor at atmospheric pressure.In addition,the catalytic activity of composite catalyst Na-Fe was studied.The catalytic characteristics of Na and Fe in thd NO-char reaction were compared in detail.The results showed that the catalytic activity of Na was greatly dependent on the loading amounts,while that of Fe on temperature.TPR(temperature-programmed reaction)results showed that the catalytic activity of Na was higher than that of Fe at low temperature in the same loading amount,however,the catalytic order was the opposite at high temperature.It was observed that the Na-Fe composite catalysts had significantly higher catalytic activity than that of Na or Fe catalyst with the same loading amount.High NO reduction was achieved by the composite ca- talyst supported on coal char without any additional reducing agent.The high catalytic activity of the two-component composite catalyst was attributed to the better dispersion of Na on char surface with the aid of FeOOH.Some synergistic effect may also be responsible for the high activity of the composite catalyst.