Hydrotalcite-Derived Mixed Metal Oxides as Catalyst Precursors for Methanol, Ethanol and Toluene Oxidation

One of the most serious threats linked to the development of civilization is the growing amount of human-generated pollution released into the environment. These include volatile organic compounds (VOCs), a significant group of air pollutants found in all urban and industrial regions. They are characterized by high volatility, reactivity, and toxicity, which contribute to declining health in living organisms and to the formation of tropospheric ozone and photochemical smog. In this review, the sources of selected alcohols (i.e., methanol, ethanol) and toluene as the representative VOCs are discussed. Furthermore, the oxidation of these VOCs is reviewed over an important class of catalysts, which are multicomponent hydrotalcite-derived mixed metal oxides. The discussion about structure–property activity correlations is followed by a review of the most active and selective catalyst for each model molecule. Finally, the reaction mechanisms are discussed in the view of the existing literature, followed by the outcome. This review provides useful guidance for the rational design and development of advanced metal oxide catalysts for VOCs degradation, with particular relevance to practical industrial applications.