DFT Analysis of the Reaction Paths of Formaldehyde Decomposition on Silver

Elucidating the Reactivity of Oxygenates on Single-Atom Alloy Catalysts

Doping isolated transition metal atoms into the surface of coinage-metal hosts to form single-atom alloys (SAAs) can significantly improve the catalytic activity and selectivity of their monometallic counterparts. These atomically dispersed dopant metals on the SAA surface act as highly active sites for various bond coupling and activation reactions. In this study, we investigate the catalytic properties of SAAs with different bimetallic combinations [Ni-, Pd-, Pt-, and Rh-doped Cu(111), Ag(111), and Au(111)] for chemistries involving oxygenates relevant to biomass reforming. Density functional theory is employed to calculate and compare the formation energies of species such as methoxy (CH3O), methanol (CH3OH), and hydroxymethyl (CH2OH), thereby understanding the stability of these adsorbates on SAAs. Activation energies and reaction energies of C-O coupling, C-H activation, and O-H activation on these oxygenates are then computed. Analysis of the data in terms of thermochemical linear scaling and Bro̷nsted-Evans-Polanyi relationship shows that some SAAs have the potential to combine weak binding with low activation energies, thereby exhibiting enhanced catalytic behavior over their monometallic counterparts for key elementary steps of oxygenate conversion. This work contributes to the discovery and development of SAA catalysts toward greener technologies, having potential applications in the transition from fossil to renewable fuels and chemicals.

Effect of preparation method of noble metal supported catalyts on formaldehyde oxidation at room temperature: Gas or liquid phase reduction

Formaldehyde (HCHO) is toxic to the human body and is one of the main threats to the indoor air quality (IAQ). As such, the removal of HCHO is imperative to improving the IAQ, whereby the most useful method to effectively remove HCHO at room temperature is catalytic oxidation. This review discusses catalysts for HCHO room-temperature oxidation, which are categorized according to their preparation methods, i.e., gas-phase reduction and liquid-phase reduction methods. The HCHO oxidation performances, structural features, and reaction mechanisms of the different catalysts are discussed, and directions for future research on catalytic oxidation are reviewed.

Co-embedded sulfur vacant MoS2 monolayer as a promising catalyst for formaldehyde oxidation: a theoretical evaluation

In this work, we theoretically evaluated the complete catalytic oxidation of formaldehyde (HCHO) catalyzed by a cobalt embedded sulfur vacant MoS2 (COSv–MoS2) monolayer.

The O, OH and OOH-assisted selective coupling of methanol on Au–Ag(111)

Molecular oxygen can be activated via a hydroperoxyl (OOH) intermediate by taking a hydrogen atom from co-adsorbed methanol.