Hydrolysis of mechanically pre-treated cellulose catalyzed by solid acid SO4^2--TiO2 in water–ethanol solvent

An efficient catalyst SO4^2--TiO2(ST) from industrial metatitanic acid has been successfully prepared to catalyze hydrolysis of ball-milling cellulose. The results show that the highest catalytic efficiency is obtained for ST calcined at 450 ℃(ST-450) with the yield of 21.8% glucose, 13.0% 5-HMF and 4.2% furfural at 200 ℃ for30 min. The ball milling of cellulose and solid acid catalyst significantly enhances the cellulose hydrolysis. The high Lewis to Bronsted acid sites ratio for ST-450 induced by bidentate ligands between SO4^2-and TiO2 benefits high organics yield, and high total acid sites contribute to the high cellulose conversion. The large pore volume of 0.29 cm^3·g^-1 and appropriate pore size of 7.35 nm of ST-450 also contribute to the high performance. High reaction temperature over 200 ℃ exhibits negative effect on glucose and 5-HMF yield due to undesired side reactions, while furfural product is stable in the reaction system. The bidentate ligands between SO4^2-and TiO2 are considered as active acid sites for cellulose hydrolysis in water–ethanol solvents.

Study on the pinene isomerization catalyzed by TiM

The isomerization reaction of pinene is one of the most important chemical reactions in the deep processing of pinene. The purpose of this study is to improve the performance of the metatitanic acid by composite. The composite metatitanic acid catalyst TiM was prepared by adding Mn elements in the preparation process. The catalytic performance of TiM was evaluated. Comparison of TiM and metatitanic acid catalyst(Ti-FGP), the reaction rate of TiM catalyst was faster, and after the reaction, the yield of camphene and tricyclene increased about 1%. The catalysts were characterized by an SEM, FT-IR and laser particle size analyzer. The results show that the pinene isomerization reaction requires the synergistic action of the Br?nsted acid and Lewis acid.Br?nsted acid has great influence on the activity of catalyst, and Lewis acid has a great influence on the selectivity of the catalyst. The structure and morphology of the catalyst have a certain effect on the selectivity of pinene isomerization reaction.

Investigation on process mechanism of a novel energy-saving synthesis for high performance Li_(4)Ti_(5)O_(12) anode material

Li_(4)Ti_(5)O_(12)(LTO) anode material demonstrates superior cycling performance due to its stable spinel structure and high lithiation/de-lithiation potential.Herein,a novel energy-saving solid-phase synthesis route for LTO has been successfully designed,employing the cheap industrial intermediate product of metatitanic acid (HTO) as titanium source.Through the in-situ Fourier transform infrared spectroscopy (FTIR)and ex-situ X-ray diffraction (XRD),it is revealed for the first time that the amorphous crystal structure of HTO is more conducive for the Li+insertion,making it possible to prepare LTO at a relatively lower sintering temperature.Utilizing the dehydration carbonization reaction between glucose and sulfuric acid,an ingenious strategy of glucose pre-coating is adopted to avoid the generation of Li_(2)SO_(4) impurity caused by the residual sulfuric acid on the surface of HTO,which meanwhile enhances the conductivity and inhibits the particle growth of LTO.The obtained ALTO@C anode material consequently exhibits excellent electrochemical performance that 132.0 m Ah g^(-1)is remained even at 20 C,and ultra low decay rate of 0.015% per cycle is achieved during 1000 cycles at 2 C.Remarkably,LiCoO_(2)//ALTO@C full cell delivers conspicuous low-temperature property (130.7 m Ah g^(-1)at 0.5 C and almost no attenuation after 300 cycles under-20℃).