Title: CHARACTERIZATION OF SURFACE ACIDITY AND CATALYTIC ABILITY OF NATURAL CLAY MINERALS BY MEANS OF TEST CATALYTIC REACTION |
Authors: Novikova Lyudmila, Belchinskaya Larissa, Roessner Frank and Alsawalha Murad |
DOI: 10.13168/AGG.2013.0048 |
Journal: Acta Geodynamica et Geomaterialia, Vol. 10, No. 4 (172), Prague 2013 |
Full Text: PDF file (0.4 MB) |
Keywords: test catalytic reaction; methylbutynol conversion; surface acidity; clay minerals |
Abstract: Catalytic test reaction of methylbutynol (MBOH) conversion was applied to investigation of natural clays and non-clay
minerals from Jordanian (bentonite, kaolinite, diatomite, zeolite) and Russian (palygorskite, kaolinite, hydromica) deposits as
well as H-ZSM-5. Palygorskite and kaolinite containing samples have shown the highest catalytic activity. Conversion over
Jordanian clay minerals decreased in the order: zeolite > bentonite > red kaolinite > white kaolinite > diatomite that agreed to
change of acidity, surface area of samples. Sufficient deactivation was observed for H-ZSM-5, kaolinite and hydromica due to
adsorption of secondary product in micropores of raw minerals. Products of both acidic and basic pathways of test reaction
were formed indicating the presence of acid and basic sites on clays surface, apart from acidic catalyst H-ZSM-5. The yield
ratio of acidic to basic products was above the unity for zeolite, bentonite, red kaolinite, and palygorskite; equal to unity for
diatomite and hydromica, and less then unity for white kaolinite. It was observed for kaolinite containing sample that high
activation temperature increased conversion of MBOH owing to formation of additional basic sites as a result of mineral
dehydroxylation. Rise of montmorillonite content from 30 to 80 % provided 91-97 % of MBOH conversion. |