Catalytic Conversion of Isopropanol and CO Oxidation in Presence of NiO Supported on Modified Cordierite

Abstract

A commercial cordierite sample showed a small catalytic activity in isopropanol conversion carried out at 150-350 ºC and no measurable activity in CO oxidation by O 2. On the other hand, supporting NiO on Al 2 O 3-modified cordierite resulted in the formation of an active solid that having good catalytic activity in isopropanol conversion and CO oxidation by O 2. These two reactions were carried out at 150-350 and 200 ºC, respectively. The results revealed that the catalyst containing 5% (w/w) NiO showed the highest activity in the alcohol conversion and acted as selective dehydration catalyst. The catalyst sample containing 20% NiO (w/w) exhibited a good activity in CO oxidation by O 2 which decreased progressively by increasing its calcination temperature within 350-600 ºC. Al 2 O 3-treated cordierite dissolved a portion of NiO in its lattice, increasing the calcination temperature within 350-600 ºC increases the dissolution of NiO in the matrix of Al 2 O 3-modified cordierite system.

Physicochemical Properties of Nanosized CuO-ZnO System as Being Doped With by Mg²⁺-Species Towards Acetone Formation From Isopropanol

“…The computed ¯k 40 o C values were 5.37x10 -3 , 4.84x10 -3 , 6.52x10 -3 and 15.47x10 -3 min -1 .m -2 for pure and solids doped with 0.75, 1.5 and 3 mol%, 10 respectively. The maximum increase in the ¯k 40 o C value attained about 2.9-fold for the heavily doped samples precalcined at 400 o C. The decrease in the catalytic activity due to increasing the calcination temperature may be due to the decrease in the surface concentration of Cu species (catalytically active constituent in H 2 O 2 decomposition), and also due to an effective increase in the crystallite size and degree of ordering of phases present via grain growth (El-Molla, et al, 2011a). Decomposition of hydrogen peroxide over the investigated system takes place on the following ion pairs Zn 2+ -Cu 2+ , Mg 2+ -Cu 2+ ion pairs.…”

“…(iii) Increasing the calcination temperature of the various investigated catalysts from 400 to 800 ºC decreased the catalytic activity of pure and variously MgO-doped solids. This decrease could be attributed to the effective increase in the crystallite size and degree of crystallinity of the active phase (El-Molla et al, 2011a) and also due to a decrease in the surface concentration of Cu-species as shown in Table 1. (iv) By increasing the calcination temperature from 400 to 800 ºC resulted in the formation of small quantities of propene with subsequent disappearance the condensation product for the reaction carried out over all MgO-doped samples.…”