SiW_（12）／Al_2O_3的硫化与加氢脱氮活性

SULFIDING AND RELATED HDN ACTIVITY OF SiW_(12)/Al_2O_3 CATALYST

为对ＳｉＮｉ（Ｃｏ）Ｗ１１（Ｍｏ１１）双金属Ｋｅｇｇｉｎ型杂多酸作为模型前身物，载于Ａｌ２Ｏ３上应用于加氢精制催化剂活性相的研究提供依据和参考，本文研究了ＳｉＷ１２在Ａｌ２Ｏ３上的分散状态，硫化行为及其加氢脱氮活性．用吸附法和浸渍法均可将ＳｉＷ１２稳定和高分散地担载于Ａｌ２Ｏ３表面上．在Ａｌ２Ｏ３载体上，ＳｉＷ１２的硫化反应发生在５７３～６７３Ｋ狭窄温度范围内，该硫化作用起始于其Ｋｅｇｇｉｎ结构破裂前，但接近硫化完全时其Ｋｅｇｇｉｎ结构已经破裂并最终形成．ＷＳ２．虽然以ＳｉＷ１２为前身物时其ＨＤＮ活性相仍为ＷＳ２，但在Ａｌ２Ｏ３表面上，由ＳｉＷ１２直接硫化比以偏钨酸为前身物得到的相应催化剂的吡啶加氢活性高得多．

In order to provide basis for the study-of heteropoly acids with SiNi(Co)W11(Mo11) double metal Keggin structure as model precursor using onhydrotreating catalyst, the existing state of SiW12 heteropoly acid on Al2O3,sulfiding performance and related hydrodenitrogenation (HDN) activity were studied. TIt results showed that SiW12 is stable and exists in high dispersity on Al2O3 surface of SiW12/Al2O3 samples prepared by adsorption and impregnation methods respectively. Sulfiding reaction of SiW12 supported on Al2O3occurred in a narrow temperature range of 573-673 K. When SiW12 was sulfided completely, its Keggin structure is destroyed and becomes finally into WS2. This WS2/Al2O3 catalyst using SiW12 as precursor is more active forHDN of pyridine than that of using metatungstate as a precursor, though the active phase is still WS2 when the SiW12 is used.