@article {46595, title = {Mixed metal oxide: a new class of catalyst for methanol activation}, journal = {Applied Surface Science}, volume = {534}, year = {2020}, month = {DEC}, pages = {147449}, type = {Article}, abstract = {

In this work, we propose a mixed metal oxide as a catalyst and demonstrate it{\textquoteright}s ability to not only activate the MeOH molecule upon adsorption but also dissociate O-H and one of it{\textquoteright}s C-H bonds. MeOH activation is compared on two prominent facets of ZnAl(2)O(4 )viz. (2 2 0) and (31 1). While spontaneous O-H bond dissociation is observed on both facets, C-H bond dissociates only on the (3 1 1) surface. Multiple factors like atomic arrangement and steps on the surface, coordination of surface atoms, and their effective charges have a combined effect on MeOH activation. The (3 1 1) surface offers higher catalytic activity in comparison with (2 2 0) surface. Having a stepped surface, availability of multiple sites, and variation in the charge distribution are some of the reasons for better catalytic performance of (3 1 1) facet. Effect of orientation of MeOH with respect to the surface adds both, information and complexity to the problem. Observations pertinent to understanding this effect are also reported. A detailed analysis of atomic arrangement on the two surfaces provides a rationale as to why MeOH gets dissociated spontaneously on the mixed metal oxide. The promising results reported here opens up a new class of catalyst for research.

}, keywords = {DFT, MeOH, Spontaneous dissociation, ZnAl2O4}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2020.147449}, author = {Mehta, Shweta and Agarwal, Sheena and Kenge, Nivedita and Mekala, Siva Prasad and Patil, Vipul and Raja, T. and Joshi, Kavita} } @article {48021, title = {Microwave-assisted selective N-alkylation of aniline over molybdenum supported catalyst}, journal = {Catalysis Communications}, volume = {168}, year = {2022}, month = {AUG}, pages = {106464}, type = {Article}, abstract = {

Selective N-alkylation of aniline is a tough and challenging reaction due to over alkylation, therefore, catalyst with specific characteristics is needed to accomplish such transformations. In this work, a series of catalysts with molybdenum supported on alumina are prepared and subjected to various reaction conditions, out of which 30 PMA (Phosphomolybdic acid) showed the best result due to its proper combination of acidic sites. This reaction is sustainable and environmentally friendly as it is carried out with methanol as an alkylating source in the presence of microwave radiation at low temperature. The reaction data was compared with various other reactor systems too.

}, issn = {1566-7367}, doi = {10.1016/j.catcom.2022.106464}, author = {Bhatkar, Akash and Mane, Samruddhi and Mekala, Siva Prasad and Gogoi, Pranjal and Mohapatra, Gourab and Ramakrishnan, Archana and Marimuthu, Prabu and Thirumalaiswamy, Raja} } @article {48765, title = {MnXWO4 nanostructure-based catalysts for single-step oxidation of cyclohexane and methane to oxygenates}, journal = {ACS Applied Nano Materials}, volume = {6}, year = {2023}, month = {APR}, pages = {7245-7258}, type = {Article}, abstract = {

Activation of the C-H bond in cyclohexane (CYH) and methane is a crucial step to obtain desirable oxygenated products using nanostructured catalyst and is a great challenge and an efficient route to mitigate the inauspicious effects of climate change. The active sites were identified using XRD, HR-TEM, SEM, N2 sorption analysis, TPR, Raman, XPS, TGA, in situ DRIFT, XAS, etc. In optimal reaction conditions, 46\% of CYH was converted into adipic acid (AA) on MnxWO4 nanostructures within 6 h. The recyclability test confirmed the catalyst heterogeneity, which revealed no appreciable loss of catalytic activity even after three consecutive reactions. In situ DRIFT study reveals that CYH is oxidized to cyclohexanone and cyclohexanol (KA oil) and is further oxidized to AA via carboxylate intermediates. DFT studies disclosed that MnOx species are responsible for the C-H activation of CYH, and the Mn2+/Mn3+ redox centers play a vital role in the absorption of KA oil to form AA. Herein, we demonstrated the significant role of the {\textquoteleft}{\textquoteleft}MnOx{\textquoteright}{\textquoteright} species and that adequate Lewis and Bronsted acidic sites, redox centers of (Mn2+/Mn3+), and lattice oxygen are accountable for the CYH conversion toward the AA. Additionally, we have reported the oxidation of methane to methanol (146 mu mole per gram of catalyst) in the presence of water at 75 degrees C without over-oxidation products.

}, keywords = {Adipic Acid, C-H bond activation, Cyclohexane oxidation, methane activation, MnOx chain, Redox center}, doi = {10.1021/acsanm.3c00319}, author = {Prabu, Marimuthu and Manikandan, Marimuthu and Samal, Pragnya Paramita and Gurrala, Lakshmi Prasad and Mekala, Siva Prasad and Archana, Ramakrishnan and Nayak, Chandrani and Bhattacharyya, D. and Jha, S. N. and Krishnamurty, Sailaja and Raja, Thirumalaiswamy} }