Catalytic Evaluation of Hafnium Modified SiO[sub.2] for the Dehydration of Alcohols

• Published in: Applied sciences Vol. 13; no. 14
• Main Authors: Esteban Benito, Heriberto, García Alamilla, Ricardo, García Serrano, Luz Arcelia, Paraguay Delgado, Francisco, Carmona García, Juan Antonio
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-07-2023
• Subjects: Alcohols; Chemical industry; Hafnium; Herbicides; Methyl ether; Olefins; Pesticides industry; Silicates; Mexico
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app13148541

The influence of hafnium metal (Hf) and sulfate ions (SO[sub.4] [sup.2−]) on the acidic properties of SiO[sub.2] mesopores synthesized by a non-hydrothermal method was studied using the following characterization techniques; TG-DTG, XRD, BET, SEM, TEM, EDS, FTIR, n-butylamine titration, FTIR-pyridine, and alcohol dehydration. The incorporation of 3.6% mol of Hf during the silicate synthesis step caused the characteristic structural arrangement of MCM-41 to collapse. However, an increase in the acid strength of the catalyst of up to 315 mV was observed, with Brönsted and Lewis-type acid sites being mostly present therein. Furthermore, the acidity of Hf- and (SO[sub.4] [sup.2−]) -modified SiO[sub.2] in the dehydration of ethanol and methanol was evaluated, resulting in a selectivity towards ethylene and dimethyl ether, respectively. Acid solids have enormous potential to produce important compounds for the chemical industry using alternative routes other than petrochemical processes. They also represent a significant advance for biorefineries.