Wang Guiru

Side-chain alkylation of toluene with methanol on KX/KZSM-5 binary zeolite catalysts

The side-chain alkylation of toluene with methanol catalyzed by the modified binary zeolite catalysts of KX and Al 2 O 3 , KX, KY, KM, or KZSM-5 has been studied. It was found that the selectives of styrene increased with the partial charge on the (A10 4 ) − tetrahedra in the second zeolite component. The KX/KZSM-5 binary zeolite catalysts had much higher activities than did the separate zeolite catalysts, and the catalytic properties were greatly improved after H 3 BO 3 and KOH modifications. Comparing the alkylation data with the t.p.d. measurements of NH 3 and CO 2 , Sandersons electronegativity, and the partial charge on the (A10 4 ) − tetrahedra, it is concluded that the side-chain alkylation of toluene with methanol on the binary zeolite catalysts is an acid-base cooperative, selective reaction.

Ethylation of ethylbenzene to produce para-diethylbenzene

Abstract HZSM-5 Catalyst was steamed and modified by the impregnation of mixed rare-earth nitrate solution and tetraethyl orthosilicate in cyclohexane solution. The modified catalysts were then applied to the alkylation of ethylbenzene with ethylene, ethanol and crude material containing 65% ethylene to produce diethylbenzene (DEB). Alkylation over the RE-Si-ZSM-5 catalysts yielded 95–98% P-DEB. The high para-selectivity is due to the reduction in acid strength within the pores and the reduction in acid sites on the crystals external surface. These catalysts have good performance in the industrial application.

Preparation of titanium-containing large pore molecular sieve from H-Al-Beta zeolite

Abstract Ti-Al-Beta zeolite has been synthesized by gas-solid isomorphous substitution with H-Al-Beta zeolite as precursor. X-ray diffraction pattern showed that its structure was similar to that of zeolite H-Al-Beta. The only difference between their IR spectra was an extra adsorption band appearing at 960cm−1. The study of IR and UV-Vis spectra showed that Ti was incorporated into the framework of Beta zeolite and Ti was tetrahedrally coordinated as part of the framework. After the precursor was treated with acid, the incorporation of titanium became easy. With increasing acid concentration, the content of Ti into the framework increased. In addition, increasing substitution time, the content of Ti into the framework also increased.