Catalysis Today 81 (2003) 611–621 Preparation and characterisation of chemisorbents based on heteropolyacids supported on synthetic mesoporous carbons and silica Alexei Lapkin a,∗ , Bengü Bozkaya a , Tim Mays a , Luisa Borello b,c , Karen Edler b , Barry Crittenden a a Department of Chemical Engineering, University of Bath, Bath BA2 7AY, UK b Department of Chemistry, University of Bath, Bath BA2 7AY, UK c Dipartimento di Scienze dei Materiali ed Ingegneria Chimica, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy Abstract The preparation of chemisorbents based on tungsto- and molybdophosphoric acids supported on two types of synthetic mesoporous carbons and two types of mesoporous silica is described. Strong solid acids with good accessibility to acid sites may potentially be effective adsorbents for the removal of basic molecular impurities, such as amines, from ultrapure manufacturing environments. Prepared materials were characterised by scanning electron microscopy, nitrogen adsorption, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and equilibrium ammonia uptake. Composites of SBA-15 with heteropolyacids were synthesised. It was shown that the inclusion of HPAs into SBA-15 results in the loss of long range order. Adsorbents based on the HPAs impregnated into the supports with the open-pore morphology (Novacarb and SBA-15) were found to be promising materials. A composite of tungstophosphoric acid with sol–gel SiO 2 was found to have the highest ammonia uptake. © 2003 Elsevier B.V. All rights reserved. Keywords: Heteropolyacids; Clean room; Mesoporous materials; Chemisorption; Synthetic carbons 1. Introduction The development of solid acid catalysts is an ac- tive and very important area of research, underpinning the development of future “green” chemical processes. There is significant need for new catalysts active in such reactions as Friedel–Crafts acylation and alky- lation, esterification, and selective oxidation, which would substitute more conventional stoichiometric re- actions known to generate large quantities of haz- ∗ Corresponding author. Tel.: +44-1225-383369; fax: +44-1225-386894. E-mail address: a.lapkin@bath.ac.uk (A. Lapkin). ardous waste materials. At the same time porous solid acid materials of very similar physico-chemical and textural properties as solid acid catalysts may also find applications in separation processes. Removal of molecular impurities from ultrapure manufacturing environments, such as in the manufac- ture of silicon wafers, is based on the use of acidic and basic chemisorbents [1]. At present, acidic chemisor- bents are based on mineral acids, such as phosphoric and sulphuric acids, impregnated into activated car- bon and dispersed in a polymer mesh filter. Sorbents based on supported liquid acids have a number of drawbacks. The formation of insoluble salts upon re- action with primary impurities restricts access to the 0920-5861/03/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0920-5861(03)00159-7