Hydrogenation of m-dinitrobenzene over Au catalysts on magnetic supports

Population and hierarchy of active species in gold iron oxide catalysts for carbon monoxide oxidation

“…However, the exact nature of such shifts could be the result of many factors in such complex catalyst systems. It could be due to (i) the reduction of Au species 18 (ii) an easier decomposition of Fe-hydroxide species due to electronic interaction between Au and iron oxides 19 20 , (iii) a Au-catalysed hydrogenation reaction 21 or (iv) some combination of these effects The magnitude of the shift and change of the peak shapes are also sensitive to parameters such as Au loading 22 . Nevertheless, we did observe a similar TPR behaviour between the CP-2 and the DP-2 catalysts, suggesting that the the metal/support interaction in these catalysts bear some resemblance to each other.…”

Selective Hydrogenation of m-Dinitrobenzene to m-Nitroaniline over Ru-SnOx/Al2O3 Catalyst

“…From environmental and economic points of view, catalytic, selective hydrogenation of m-DNB directly to m-NAN should be an attractive process, and it has attracted much attention in recent years [1][2][3]. However, controlling the product selectivity is particularly a challenge in the hydrogenation of m-DNB in terms of the exclusive formation of m-NAN (partial reduction product), due to it being easily hydrogenated to the complete reduction product of m-phenylenediamine (m-PDA) [4,5] and the formation and accumulation of intermediates, such as phenylhydroxylamine (PHA), azoxy-benzene (AOB), azo-benzene (AB) and hydrazo-benzene (HAB), as illustrated in Scheme 1. Hence, developing an efficient catalytic system for achieving high selectivity to m-NAN is a hot topic and has achieved some progress.…”

“…Over Pd/C and Pt/C catalysts, the reaction condition has significant effects on the product selectivity. Supported Au catalysts, such as Au/Al 2 O 3 , Au/Fe 2 O 3 and Au/TiO 2 , could deliver 100% selectivity to m-NAN at about a 10% conversion of m-DNB [7][8][9][10]; however, the highest selectivity to m-NAN could not achieve 90% after conversion reached above 70%, due to m-NAN being further hydrogenated to m-PDA [5,8,11]. Ru/C was found to be efficient in the selective partial hydrogenation of o-, m-and p-DNBs, and the selectivities to the corresponding NANs achieved over 95% [3].…”

Carbon supported gold and silver: Application in the gas phase hydrogenation of m -dinitrobenzene

“…A decrease in peak intensity and increase in line width were observed at the lower loading as noted elsewhere [58] with a measurable shift to lower BE values (by 0.3-0.4 eV, see Table 1). Martínez et al [59] investigating 1%wt. Au/Fe 3 O 4 (9.0 nm, Au 4f 7/2 BE = 83.8 eV) and Au/SiO 2 (5.7 nm, Au 4f 7/2 BE = 82.6 eV) linked the downshift in BE to the formation of Au ␦− as a result of electron transfer from the support.…”