Semiconductivity and catalytic activity. The dehydrogenation of isopropyl alcohol on ZnO$z.sbnd;Cr2O3 catalysts

Synergistic Effect of Photocatalyst CdS and Thermalcatalyst Cr2O3-Al2O3 for Selective Oxidation of Aromatic Alcohols into Corresponding Aldehydes

“…When the CAO catalyst is heated, the oxygen atoms (Oσ) and chromium atoms (Cr) on the surface of Cr 2 O 3 interact with hydrogen (H) and oxygen (O) in the alcoholic hydroxyl group, respectively. The hydrogen of the hydroxy group (−OH) and the hydrogen (Hα) of the benzyloxy group (ArC­(Hα) 2 O−) shift to Oσ and Cr, respectively. ,, Then, a proton and the benzyloxy group (ArCH 2 O−) are bounded and formed to O and Cr of Cr 2 O 3 , respectively. In other words, the H of the −OH group and the Hα of the benzyloxy group interact with Cr 2 O 3 , which weaken bonds of the O–H and the C–Hα, respectively.…”

“…Cr 2 O 3 -Al 2 O 3 (CAO) happens to be a commonly used thermocatalytic dehydrogenation catalyst in the industry. Its excellent thermocatalytic dehydrogenation effect has been reported widely. − In the CAO catalyst, the bulky porous Al 2 O 3 acts as a carrier to allow Cr 2 O 3 to be well embedded therein; Al 2 O 3 has excellent thermal conductivity, which makes Cr 2 O 3 more convenient to heat evenly . When the CAO catalyst is heated, the chromium atom (Cr) and an oxygen atom (Oσ) on the surface of Cr 2 O 3 interact with oxygen (O) and hydrogen (H) of the alcoholic hydroxyl group, respectively.…”

“…The hydrogen of the hydroxy group (−OH) and the hydrogen (Hα) of the benzyloxy group (ArC­(Hα) 2 O−) shift to Oσ and Cr, respectively. In other words, the H of the −OH group and Hα of the ArC­(Hα) 2 O– group interact with Cr 2 O 3 , which weakens bonds of the C–Hα and O–H. ,, Consequently, besides the fact that UV light and visible light can be used for photocatalytic selective transformation of alcohol, the alcohol transformation can also be driven by the heating effect of thermocatalysis . On the other hand, CdS, as a very classic photocatalyst, has a good application in hydrogen generation in water decomposition and redox processes. , Under visible light illumination, CdS can be photoexcited and generate electrons and holes, electrons participate in the reduction reaction, and holes participate in the oxidation process.…”