Copper-Layered Double Hydroxide for Methanol Electrooxidation: A Combined DFT and Experimental Characterization

Exposure to volatile organic compounds (VOCs) can cause several health problems both in humans and animals. Among them, methanol (CH
3
OH), the most abundant oxygenated VOCs present in the troposphere, is a precursor of carbon monoxide (CO) and formaldehyde (CH3CHO) but it is also one of the simplest molecules used as a fuel for cleaner energy production. The aim of this research aspires to design and characterize promising advanced functional sensor-material based on CH
3
OH oxidation to either drive energy conversion, detect the methanol concentration and/or prevent environmental methanol pollution. The electrochemical methanol oxidation reaction (MOR) is a meaningful pathway to obtain these aims since the low potential is required for reaction occurrence. In the context of the development of sustainable and economic sensor-material, layered double hydroxide (LDH) based on Cu is a very promising one. Two different LDH copper-based composites were synthetized and characterized by means of X-ray diffraction experiments, electrochemical measurements, and atomistic simulations. Results showed a crucial structural role played by the type of M(II) ion present in the structure of the LDH. In particular, copper-based LDH containing Zn(II) exhibits a stronger ability to oxidize CH
3
OH than those containing Mg(II). The atomistic simulations indicate a sort of cooperative affect by the Zn(II), most probably through an enhanced adsorption phenomenon which is relevant in the mediated electron transfer by the active species Cu(III). Overall, this work highlighted the prevision potential of the in silico studies which will be useful to faster screen of different materials followed by selection and synthesis of those showing the optimal features in terms of pollutant adsorption and structure stability. This combined experimental-in silico approach could therefore lead to a faster design and optimization of effective functional materials for applications in indoor and outdoor quality.