02063nas a2200205 4500008004100000022001400041245010300055210006900158260000800227300001100235490000800246520139700254653000801651653000901659653002501668653000801693100001801701700001801719856012001737 2022 eng d a0169-433200aFrom molecular adsorption to decomposition of methanol on various ZnO facets: a periodic DFT study0 aFrom molecular adsorption to decomposition of methanol on variou cNOV a1541500 v6023 a

Methanol is an interesting and important molecule to study because of its potential to replace existing fuels. It is also a prominent hydrogen source which can be used to generate hydrogen in-situ. ZnO is widely used as catalyst in synthesis of methanol from CO2 at industrial scale. In this work, we demonstrate that the same catalyst could be used for MeOH decomposition. We have investigated interaction of methanol with various flat and stepped facets of ZnO by employing Density Functional Theory (DFT). Two flat [(10(1)overbar 0) and (11(2)overbar 0)] and two stepped [(10(1)overbar 3) and (11(2)overbar 2)] facets are studied in detail for methanol adsorption. Chemisorption of MeOH with varying strength is common to all four facets. Most importantly spontaneous dissociation of O-H bond of methanol is observed on all facets except (11(2)overbar 0). Our DFT calculations reveal that molecular adsorption is favored on flat facets, while dissociation is favored on step facets. Also, (10(1)overbar 0) facet undergoes substantial reconstruction upon MeOH adsorption. Activation of C-H bond along with strengthening of C-O bond on ZnO facets suggest partial oxidation of methanol. With our DFT investigations, we dig deeper into the underlying electronic structure of various facets of ZnO and provide rationale for the observed facet dependent interaction of ZnO with MeOH.

10aDFT10aMeOH10aSurface interactions10aZnO1 aMehta, Shweta1 aJoshi, Kavita uhttp://library.ncl.res.in/content/molecular-adsorption-decomposition-methanol-various-zno-facets-periodic-dft-study01604nas a2200217 4500008004100000022001400041245009500055210006900150260000800219300001100227490000800238520091100246653000801157653002601165653001301191653002101204653000801225100001801233700001801251856011701269 2023 eng d a0039-602800aElectronic fingerprints for diverse interactions of methanol with various Zn-based systems0 aElectronic fingerprints for diverse interactions of methanol wit cOCT a1223500 v7363 a

We have investigated various Zn-based catalysts for their interaction with methanol (MeOH). MeOH is one of the most critical molecules being studied extensively, and Zn-based catalysts are widely used in many industrially relevant reactions involving MeOH. We note that the same element (Zn and O, in the present study) exhibits different catalytic activity in different environments. The changing environment is captured in the underlying electronic structure of the catalysts. In the present work, we compared the electronic structure of Zn-based systems, i.e., ZnAl2O4 and ZnO along with oxygen preadsorbed Zn (O-Zn) and metallic Zn. We demonstrate the one-to-one correlation between the pDOS of the bare facet and the outcome of that facet's interaction (i.e. either adsorption or dissociation of MeOH) with MeOH. These findings would pave the way towards the in-silico design of catalysts.

10aDFT10aElectronic properties10aMethanol10aZn-based systems10aZnO1 aMehta, Shweta1 aJoshi, Kavita uhttp://library.ncl.res.in/content/electronic-fingerprints-diverse-interactions-methanol-various-zn-based-systems01959nas a2200229 4500008004100000022001400041245009500055210006900150260000900219300001100228490000800239520124200247653000801489653001701497653000901514653000801523100001801531700002001549700002801569700001801597856011401615 2024 eng d a0169-433200aFrom digital blueprint to chemical reality: methanol to formaldehyde at ambient conditions0 aFrom digital blueprint to chemical reality methanol to formaldeh cOCT  a1605270 v6693 a

Partial oxidation of methanol to value added product presents an intriguing yet challenging process. Among these products, formaldehyde is the simplest and one of the most vital aliphatic aldehydes, which has extensive application across various domains. Industrially, silver and iron-molybdenum oxides are used as catalysts for the conversion of methanol to formaldehyde at elevated temperatures (600 degrees C and 250-400 degrees C, respectively). However, in this computational and experimental study, we have demonstrated the efficacy of ZnO as a catalyst. Notably, in the presence of ZnO, methanol readily converts to formaldehyde even under ambient conditions. We employed periodic density functional theory (DFT) to explore (10 1 1) facet of ZnO to elucidate its interaction with methanol. Our comprehensive analysis identified the most active facet (10 1 1) involved in the spontaneous conversion of methanol to formaldehyde. Subsequently, experimental validation supported our theoretical findings, demonstrating the conversion of methanol to formaldehyde with 100% selectivity at room temperature and atmospheric pressure in the presence of ZnO. This study exemplifies the pivotal role of theory in catalyst design.

10aDFT10aFormaldehyde10aMeOH10aZnO1 aMehta, Shweta1 aKasabe, Mirabai1 aUmbarkar, Shubhangi, B.1 aJoshi, Kavita uhttp://library.ncl.res.in/content/digital-blueprint-chemical-reality-methanol-formaldehyde-ambient-conditions