Gas Phase Dehydration of Glycerol to Acrolein Over Nickel Phosphate Catalysts

We investigated the catalytic performance of glycerol conversion to acrolein on nickel phosphates samples (NiP-T (T = 300,400,500,600, and 700 °C)). The textural property, acidity of the fresh catalyst and carbon content of the used NiP-500 were also determined. The results showed that NiP was amorphous under the appropriate calcination temperature. The textural property, acid amount and strength were important in this reaction. Glycerol conversion was proportional to the acid amount of the sample. After 2 h on stream, NiP-500 with the largest pore size, largest acid amount and largest number of moderate acid sites had the maximum catalytic performance (89% glycerol conversion and 64% acrolein selectivity). NiP-700 showed the lowest performance (48% glycerol conversion and 34% acrolein selectivity), which is due to the lowest surface area, pore size and the lowest acid amount of NiP-700. Moreover, the catalyst deactivation was ascribed to carbon deposition on phosphates during the reaction.

High Acid Biochar-Based Solid Acid Catalyst from Corn Stalk for Lignin Hydrothermal Degradation

Solid acid catalysts generally show the disadvantage of low acid amount and low recycling rate. To solve these problems, corn stalk-based solid acid catalysts were synthesized through carbonization and sulfonation processes in this work. The results showed that besides the rod-like structure inherited from raw corn stalk, the catalysts contained some small broken pieces on the surface, and the specific surface area varied from 1120 to 1640 m2/g. The functional groups (-SO3H) were successfully introduced onto the surface of the obtained solid acid catalysts. The acid amount varied between 1.2 and 2.4 mmol/g, which was higher than most of solid acid catalysts. The catalyst produced at 800 °C for 6 h in carbonation and then at 150 °C for 8 h in sulfonation had larger specific surface area and more sulfonate groups. In the degradation of lignin, the use of catalyst led to the generation of more aromatic compounds (65.6 wt. %) compared to that without using the catalyst (40.5 wt. %). In addition, a stable yield of reaction (85%) was obtained after four reuses. Therefore, corn stalk is suitable for high-value utilization to prepare high-acid amount biochar-based catalyst.

Synthesis, characterization, and catalytic application of hierarchical nano-ZSM-5 zeolite

The crystal size and strong acid amounts of ZSM-5 decrease and the mesopores increase with increasing of KH-560. High MTA catalytic performance could be obtained under synergistic effect of proper strong acid amount, smaller crystal size and abundant hierarchical structure.

Effect of support composition on the structural and catalytic properties of Ru/AlOOH–SiO2catalysts for benzene selective hydrogenation

A volcano-type correlation between the acid amount and cyclohexene selectivity over the Ru/AlOOH–SiO2catalysts was elucidated in benzene selective hydrogenation.

Usage of Neural Network to Predict Aluminium Oxide Layer Thickness

This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage) and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A·dm−2and 3 A·dm−2for creating aluminium oxide layer.

Designing of In Situ FTIR Cell and its Application

An easy-operation in-situ FTIR cell is designed and used for the investigation of dehydroxylation and pyridine adsorption FTIR study. The dehydroxylation FTIR spectra of MCM-41 indicate that the isolated, geminal, and oxygen perturbed silanol vibrated at about 3745, 3735 and 3520 cm-1, respectively. Py-FTIR spectra indicate that MCM-41 has none Lewis and Brönsted acid sites while the acid amount and acid strength of AlMCM-41 increase with the decrease of Si/Al.