ISSN 0004-881X

Nanoengineering X/AlOOH-Al₂O₃ Sols by Sequential Adsorption to Produce Xerogel Ceramic Catalytic Films for Environmental Pollution Control and Nanoparticles for BaSO₄ Scale Control in Water

by P.A.Sermon ^1*, M.Worsley ¹, S.A.E.Abdulla ² and I.R.Collins³

1) Nanomaterials Laboratory, The Wolfson Centre for Materials Processing, Brunel University, Uxbridge, Middx., UB8 3PH;
2) Chemistry Division, University of Surrey, Guildford, GU2 7XH;
3) Exploration and Production Technology, BP Exploration Co.Ltd., Sunbury-on-Thames, Middx.

Email: paul.sermon@brunel.ac.uk

Abstract

Colloidal AlOOH (90-100nm in average size but with needle-like morphology) has been prepared by sol-gel routes. Then a sequential adsorption route has been used to nanoengineer novel catalysts and BaSO₄ - scale control agents. First, it has been shown that oxalate ions (C₂O_{4 -}) can be adsorbed onto the surface of the water-dispersed colloidal AlOOH. When La³⁺_(aq) and Co³⁺_(aq) (or Ba²⁺_(aq) and Ce⁴⁺_(aq)) are introduced to dispersed oxalate/AlOOH, then the cations adsorb and the M₁-M₂/oxalate/AlOOH forms. This produces fractal ceramic film coatings and after drying and calcinations LaCO₃/AlOOH (or BaCeO₃/AlOOH) and then highly-dispersed LaCO₃/Al2O3 (or BaCeO₃/Al2O3) are formed. These have useful catalytic activity in CO oxidation. We expect to show that one can fine-tune the M₁-M₂ pair and loading to give the lowest CO conversion light-off temperatures. Second, it has also been demonstrated that sulfate anions adsorb onto water-dispersed colloidal AlOOH without destabilizing this and then Ba²⁺_(aq) adsorb onto SO₄^2--/AlOOH to give BaSO4/AlOOH. Thus the AlOOH nanoparticulate chaperones ensure BaSO₄ grows safely when water rich in Ba²⁺_(aq) is introduced. This may be useful in barite scale control in oil-wells worldwide.

Full Paper (PDF) | Table of Contents