The applications of clay-based structured materials, excluding cordierites, for environmental protection are examined. In particular, their use in the abatement of some of the main hazardous species in polluted emissions such as nitrogen oxides, carbon monoxide, volatile organic compounds and heavy metals is discussed. A distinction is made between adsorption and catalytic processes. In addition, a general overview of the methods and general principles followed to prepare structured materials from clays is also given. Special attention is paid to those employed to obtain honeycomb monoliths and foams. (C) 2010 Elsevier BM. All rights reserved.