类水滑石复合金属氧化物的制备及催化分解N_2O的性能研究

The preparation of hydrotalcite-like composite metal oxides and investigation on N_2O catalytic decomposition

采用共沉淀法制备了一系列类水滑石金属氧化物作为催化剂,并采用X射线荧光光谱(XRF)、BET分析、傅立叶变换红外光谱(FTIR)、X射线衍射(XRD)和扫描电子显微镜(SEM)等手段对其进行了表征分析。结果表明,所制备的催化剂经过530℃焙烧仍基本保持了类水滑石的结构特征。催化剂表面CO_2吸附态大概可以划分为3种,即300℃以下的低温吸附态、300～550℃的中温吸附态及550℃以上的高温吸附态。催化剂催化分解N_2O性能的变化规律基本与其表面碱性变化相符。含La、Mg、Al的类水滑石复合金属氧化物催化剂具有较好的催化分解N_2O的稳定性。

A series of hydrotalcite-like metal oxides were prepared by coprecipitation method and characterized by various means,such as X-ray fluorescence spectrum(XRF),Brunauer-Emmett-Teller(BET)test,Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and scanning electron microscope(SEM).Results showed that the hydrotalcite-like structure was basically remained after calcination at 530 ℃.CO2 adsorption on the surface of catalysts could be generally divided into three states,namely temperature below 300 ℃,300-550 ℃ and above 550 ℃,respectively.The variation of N2O catalytic decomposition activity of catalysts was consistent with the variation of the surface alkaline.The metal oxide containing La,Mg and Al had good stability for N2O catalytic decomposition.