A novel method for enhancing on-stream stability of fluid catalytic cracking (FCC) gasoline hydro-upgrading catalyst: Post-treatment of HZSM-5 zeolite by combined steaming and citric acid leaching

Preparation and properties of hydrocarbon dispersible HZSM-5 nanocrystals for quasi-homogeneous catalytic cracking of n-dodecane

“…This result indicates that grafting with TMCS has small effect on the total amount of Brønsted acid and Lewis acid, but changes their distribution on the surface. However, by-product HCl generated from reacting TMCS with OH groups dissolve in absolute ether to form HCl solution, which leads to the leaching of extraframework aluminum [42][43][44]. It is identified from the change of peak intensity at 27 ppm in 27 Al MAS NMR spectra that most of the pentacoordinated nonframework Al are removed after trimethylsilylation which result in sharply decrease of the total Lewis acid.…”

Pd catalyst supported on SiO2–Al2O3 xerogel for hydrocracking of paraffin wax to middle distillate

“…It is reported that acid property of the catalyst is one of the crucial factors determining the catalytic performance in the hydrocracking of paraffin wax [38,39]. Therefore, some attempts have been made to correlate the acid property with hydrocracking activity of Pd/SA-X catalysts.…”

The ZSM-5-Catalyzed Oxidation of Benzene to Phenol with N2O: Effect of Lewis Acid Sites

“…As presented in Figure 5, the NH 3 -desorption profile exhibits a broad band at the range of 313-873 K. H-ZSM-5 exhibits two desorption peaks at about 400 and 683 K, corresponding to the weak acidic sites and strong acidic sites, respectively [31]. With the ion exchange of Fe(NO 3 ) 3 , the low-temperature peak migrates to lower temperature, suggesting that the acid strength become weaker probably because of the weaker acidity of Fe-OH-Si [32], and the amount weak acidic sites for Fe/ZSM-5 decrease with ferric species incorporation into the ZSM-5 framework [33]. Both H-ZSM-5-ST and Fe/ZSM-5-ST samples show much less acid amounts than samples without water steam treatment in Table 3, due to the serious dealumination of zeolite framework [34].…”

“…Catalysts 2017, 7, x FOR PEER REVIEW 6 of 15 lower temperature, suggesting that the acid strength become weaker probably because of the weaker acidity of Fe-OH-Si [32], and the amount weak acidic sites for Fe/ZSM-5 decrease with ferric species incorporation into the ZSM-5 framework [33]. Both H-ZSM-5-ST and Fe/ZSM-5-ST samples show much less acid amounts than samples without water steam treatment in Table 3, due to the serious dealumination of zeolite framework [34].…”