一种快速合成含锆原子ZSM-5分子筛的方法

一种快速合成含锆原子ＺＳＭ－５分子筛的方法是将硅源、钠盐和去离子水配制成Ａ溶液；将铝源、酸和去离子水按摩尔比为配制成Ｂ溶液；将锆源、去离子水配制成Ｃ溶液，在剧烈搅拌下，将Ｂ溶液滴加到Ａ溶液中，然后加入有机模板剂，再加入溶液Ｃ，搅拌使其混合均匀，老化、晶化、固液分离，对滤饼干燥、焙烧２得到分子筛原粉。本发明具有合成出含锆原子ＺＳＭ－５分子筛的结晶度（９０％＞）。合成周期短，晶化时间少的优点。

一种快速合成强酸型ZSM-5分子筛的方法

一种快速合成强酸型ＺＳＭ－５分子筛的方法是按一定比例将硅源与模板剂、去离子水总量的一半配置成Ａ溶液，铝源、无机酸与另一半去离子水配置成均匀的Ｂ溶液，将Ｂ溶液滴加至Ａ溶液中，制成导向剂；再按一定比例将硅源与模板剂、去离子水总量的一半配置成Ｃ溶液，铝源、无机酸与另一半去离子水配置成Ｄ溶液，Ｄ溶液滴加入Ｃ溶液，最后再加入占总体积５－１０％的导向剂，得到强酸型ＺＳＭ－５分子筛；本发明具有合成时间短，酸性强的优点。

导向剂法快速合成ZSM-5分子筛的方法

一种导向剂快读合成小晶粒ZSM-5分子筛的方法，主要包括导向剂制备、分子筛合成两步。第一步导向剂制备首先根据配料比将硅源与无离子水制成Ａ溶液后将模板剂加入，在搅拌下再将由无机酸碱调节适当碱度的铝源滴入均匀反应，按趁虚升温完成后，将合成液体中接近透明的部分分离出即为导向剂。分子筛的合成过程同导向剂相同，只是将原料配比中的有机胺模板剂由导向剂取代，晶化过程需６５－７５小时即可完成，得到平均粒径0.1μm的ZSM5分子筛。本发明制备简单，合成周期短。

In situ preparation of Ir/ZSM-5/cordierite honeycombs and their application for NOx abatement

ZSM-5 zeolites were synthesized in situ onto cordierite honeycombs by vapor phase transport (VPT) for the first time. The as-synthesized ZSM-5/cordierite honeycombs were impregnated with IrCl3 and tested for NOx reduction with a simulated exhaust gas as the reducing agent. Under the conditions of excess oxygen, the Ir/ZSM-S/cordierite monolith catalyst exhibited NO reduction of 73% at a temperature of 573 K and a space velocity of 20,000 h(-1).

Enhanced activity of an In-Fe2O3/H-ZSM-5 catalyst for NO reduction with methane

Selective reduction of NO by CH4 on an In-Fe2O3/H-ZSM-5 catalyst was investigated in the presence of excess oxygen. Compared with In/H-ZSM-5, the In-Fe2O3/H-ZSM-5 catalyst with high Fe2O3 contents showed higher activity in a wide range of reaction temperatures. It was found that the addition of Fe2O3 yielded a promotion effect on CH4 activation. The influence of water vapor on NO conversion was also investigated. The activity of the In/H-ZSM-5 catalyst has been found to be strongly inhibited by water vapor, while the In-Fe2O3/H-ZSM-5 catalyst remained fairly active in the presence of 3.3% steam. (C) 2000 Elsevier Science B.V. All rights reserved.

Catalytic reduction of NO over in situ synthesized Ir/ZSM-5 monoliths

The catalytic performance of Ir-based catalysts was investigated for the reduction of NO under lean-burn conditions over binderless Ir/ZSM-5 monoliths, which were prepared by a vapor phase transport (VPT) technique. The catalytic activity was found to be dependent not only on the Ir content, but also on the ZSM-5 loading of the monolith. With the decreasing of the Ir content or the increasing of the ZSM-5 loading of the monolith, NO conversion increased. When the ZSM-5 loading on the cordierite monolith was raised up to ca. 11% and the metal Ir content was about 5 g/l, the NO conversion reached its maximum value of 73% at 533 K and SV of 20 000 h(-1). Furthermore, both the presence of 10% water vapor in the feed gas and the variation of space velocity of the reaction gases have little effect on the NO conversion. A comparative test between Ir/ZSM-5 and Cu/ZSM-5, as well as the variation of the feed gas compositions, revealed that Ir/ZSM-5 is very active for the reduction of NO by CO under lean conditions, although it is a poor catalyst for the C3H8-SCR process. This unique property of Ir/ZSM-5 makes it superior to the traditional three-way catalyst (TWC) for NO reduction under lean conditions. (C) 2001 Elsevier Science B.V. All rights reserved.

On the selectively catalytic reduction of NOx with methane over Ag-ZSM-5 catalysts

The catalytic performance of silver-modified ZSM-5 catalysts in the selectively catalytic reduction (SCR) of NOx with methane was investigated. NO was selectively reduced by CH4 to N-2 in the presence of excess O-2, and the catalytic activity depended on both the activation of CH4 and the adsorption properties of NOx. Silver incorporated in ZSM-5 zeolite activated CH4 at low temperatures and lowered the "light-off" temperature for the CH4-SCR of NOx. Temperature-programmed (TP) spectroscopy studies depicted that surface nitrosyl species directly decomposed to N-2 in the absence of O-2. CH4 could not effectively reduce surface nitrosyl species, but might facilitate the direct decomposition of NO through the removal of surface oxygen. Surface nitrates were formed in NO and O-2 coexisting system and could be effectively reduced by CR4 to nitrogen. The priority of surface nitrates to O-2 in the reaction with CH4 clearly demonstrated that CH4 selectively and preferentially reduced the surface nitrate species to N-2 in the excess of oxygen. (C) 2002 Elsevier Science B.V. All rights reserved.