Efficient and selective oxidation of toluene to benzaldehyde on manganese tungstate nanobars: a noble metal-free approach

Abstract

An approach to synthesize MnWO4 catalysts for the oxidation of toluene to benzaldehyde in a chlorine-free environment is demonstrated.

CuO{001} as the Most Active Exposed Facet for Allylic Oxidation of Cyclohexene via a Greener Route

“…Though zeta potential is not a direct measure of the surface charge, the interparticle forces and dispersion stability measured from it can be correlated with the surface charge [37] . A higher zeta potential value indicates higher dispersion in that particular medium, which suggests increased number of catalytic sites are available for the reaction, and negative zeta potential means that a large number of positively charged sites are available on the catalyst surface [26] . The CuO FL2 shows the highest negative zeta potential (−0.670 mV, Figure S6b) indicating that it can attract more number of negatively charged particles (cyclohexenyl peroxy radicals) onto its surface for reaction leading to a higher catalytic activity.…”

“…The concentration of different components in the product was obtained by integrating the observed GC peaks and comparing the same with pre‐calibrated peak area of the standard sample. The reactant conversion, selectivity, and yield of the products were obtained using following equations (1–3 [26] …”

“…The high conversion and selectivity of the products are crucial for a catalytic reaction. Augmenting the selectivity without affecting the conversion remains a challenge, particularly in the hydrocarbon oxidation chemistry due to the involvement of a large number of intermediates and byproducts [26,27] . For instance, cyclohexene oxidation produces several oxygenated products, such as di‐(2‐cyclohexenyl) ether, 2‐cyclohexen‐1‐one, and 2‐cyclohexen‐1‐ol, upon activation of the allylic position of cyclohexene and for the double bond position cyclohexene oxide and cyclohexane‐1,2‐diol are reported (Scheme 1).…”

“…Augmenting the selectivity without affecting the conversion remains a challenge, particularly in the hydrocarbon oxidation chemistry due to the involvement of a large number of intermediates and byproducts. [26,27] For instance, cyclohexene oxidation produces several oxygenated products, such as di-(2-cyclohexenyl) ether, 2-cyclohexen-1-one, and 2-cyclohexen-1-ol, upon activation of the allylic position of cyclohexene and for the double bond position cyclohexene oxide and cyclohexane-1,2-diol are reported (Scheme 1). [27] However, 2-cyclohexen-1-one and 2-cyclohexen-1-ol are the two main value-added products used as intermediates in the chemical industries.…”

Selective Catalytic Oxidation of Benzyl Alcohol to Benzaldehyde by Nitrates

“…Traditionally, BzH was synthesized by hydrolysis of benzal chloride or vapor/liquid-phase oxidation of toluene. In the former method, the chlorinated by-products and corresponding toxic acidic would be generated, which brought troubles to the industrial application (Mal et al, 2018;Lu et al, 2019), while the vapor/liquid oxidation of toluene was also limited because of the harsh reaction conditions and low selectivity (Miao et al, 2016). Recently, BzH production with benzyl alcohol oxidation was widely adopted in industry, based on its advantages of easy-control condition and high yield (Lv et al, 2018;Thao et al, 2018).…”