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Quinoline was synthesized via the typical Skraup approach with a vapor-phase process. The mesoporous Ni/beta zeolite catalyst exhibited high-efficiency catalytic activity and an enhanced ability of anti-deactivation.

A novel method for the synthesis of high-performanced titanium silicalite-1 (TS-1) zeolite at a very low usage of tetrapropylammonium hydroxide (TPAOH) was developed in this work. The method involved a temperature-programmed hydrothermal crystallization (TPHC) of a batch with a TPAOH/SiO 2 molar ratio of as low as 0.05, being 5 times smaller than that employed in the conventional synthesis, in which the TPAOH was entirely provided by a TS-1 precursor sol. The characterizations of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance ultraviolet− visible spectroscopy (DR UV−vis), and scanning electron microscopy (SEM) indicated that the TS-1 synthesized via the novel method possessed a uniform crystal size of ∼0.3 μm, a very high crystallinity and a considerably large content of framework Ti (2.33 mol %). The TS-1 had been employed as the catalyst for the ammoximation of cyclohexanone, of which the influencing factors were systematically investigated. It was shown that the TS-1 synthesized via the novel method possessed a very high performance, which is even better than for those synthesized via the conventional method both in this work and in the literature work.

This work presented a novel route for the synthesis of pyridine bases from glycerol and ammonia. The whole process consisted of the dehydration of glycerol to acrolein and the subsequent condensation of acrolein and ammonia to pyridine bases, with the two reactions being conducted either simultaneously over a single catalyst in a conventional fixed-bed reactor (single-stage reactor mode) or separately over two different catalysts, namely, a catalyst pair, in a series-connected fixed-bed reactor (two-stage reactor mode). Under the optimized conditions, a 32.18% total yield of pyridine bases was achieved over the HZSM-5-At-acid catalyst, while a 62.25% and 60.85% total yield of pyridine bases, without the formation of 4-picoline, could be afforded over the catalyst pairs (HZSM-5-At + ZnO/HZSM-5-At-acid) and (HZSM-22-At-acid + ZnO/HZSM-5-At-acid), respectively. The catalyst pair (HZSM-22-At-acid + ZnO/HZSM-5-At-acid) exhibited the greatest stability with time-on-stream. This was attributed to the fact that the above-mentioned two reactions were affected differently by the texture and acid properties of the catalyst, and they could be simultaneously promoted to the greatest extent over two different suitable catalysts in a two-stage reactor mode but not over a single catalyst in the single-stage reactor mode. This novel route was shown to be more green and efficient relative to those employed currently in both industrial production and the literature.

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