Cu and Co exchanged ZSM-5 zeolites: activity towards no reduction and hydrocarbon oxidation

Abstract

(y = 12, 25 and 45). The activity of the catalysts was evaluated in the reduction of NO to N 2 in an oxidative atmosphere using propane or methane as reducing agents. The Cu catalysts were only active with propane and they presented higher activity than the Co-based catalysts, the latter being active with both hydrocarbons. H 2 -TPR and DRS-UV/Vis data allowed correlation between the activity towards NO reduction and the presence of cationic charge-compensating species in the zeolite. It was also verified that the hydrocarbons are preferentially oxidised by O 2 , a reaction that occurs simultaneously with their oxidation with NO.

Effect of copper on textural and acidic properties of hierarchical nanocrystalline ZSM‐5

“…The spectra of HCu(0.2 M)NZ shows a small peak in 0 ppm, whereas for HNZ, it is found to be absent. This confirms the presence of octahedral aluminum in HCu(0.2 M)NZ and lack of octahedral aluminum in HNZ 40,71,72 . This validates that dealumination takes place on ammonium chloride treatment on HCu(0.2 M)NZ.…”

“…The existence of peaks at 212 nm in all samples in this work reveals that not much change has taken place in the Al environment. A band appears at 250 nm for HCu(0.2 M)NZ and HCu(0.5 M)NZ indicating the interaction of copper ions with zeolitic oxygen 11,40,41 . According to the literature, the dimeric, oligomeric, or aggregated copper oxide will produce bands at 430–560 nm 42–47 .…”

Comparison between leached metakaolin and leached diatomaceous earth as raw materials for the synthesis of ZSM-5

“…Unfortunately, these quaternary ammonium compounds are rather expensive. The molecule n -butylamine was reported (Sang et al 2004 , Zhao 2005 , Martins et al 2006 , Feng et al 2009 ) as an alternative templating agent to replace TPA-Br and TPA-OH and is about 100 times less expensive on a molar basis. In the past two decades, efforts have also been undertaken to identify inexpensive Si and Al sources to synthesize ZSM-5(Chareonpanich et al 2004 , Sanhueza et al 2004 , Mignoni et al 2007 , Aliev et al 2011 ) and it has been shown that kaolin clay and diatomaceous earth are two suitable and inexpensive sources of silica and alumina.…”

The potential for using a coconut shell catalyst for the selective catalytic reduction of NOxgases

“…(1) [17,18]. It can be observed for CCSC, the intensity of reduction at low temperature decreased and disappearance of shoulder at ~650 o C, which implies that the catalyst has been reduced [19].…”

“…All samples showed adsorption peaks corresponding to stretching vibration of; (1) ) [16]. Peak (1) and (4) are oxygenated surface groups, which are also the anchoring sites for metal catalysts [17]. UCSC showed a reduction in these peaks due to the used-up by Cu and Mn.…”