Enhanced stability of HZSM-5 supported copper oxides by Na doping for catalytic combustion of propene

Huang, Wenzuo; Liu, Yue; Wu, Zhongbiao

doi:10.1016/j.catcom.2019.01.018

Cited by 9 publications

(6 citation statements)

References 32 publications

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“…The peak areas at 935.2 and 955.0 eV in the XPS spectrum of 500Cu-Z were smaller than those in the Cu-Z curve. The results confirm that Cu 2+ can be converted into Cu + under high-temperature calcination, which is consistent with the results of previous studies …”

Section: Resultssupporting

confidence: 93%

“…The peak at 935.2 eV of Cu2P 3/2 is assigned to the isolated Cu 2+ . Cu 2+ and oxygen atoms on the surface of the zeolite were bonded in the form of coordination bonds. ,, Shakeup satellite peaks at 942.8 eV for Cu2P 3/2 and 962.5 eV for Cu2P 1/2 also confirmed the presence of Cu 2+ . The peaks of Cu2P 1/2 at 952.3 and 955.0 eV can be ascribed to microcrystals of Cu + /CuO and Cu 2+ , respectively.…”

Section: Resultsmentioning

confidence: 85%

“…The XPS test results in the A/pulp spectrum showed that there were no Si and Cu. In Figure d, the Cu element mainly existed in ionic form, including Cu + (934.5 eV) and Cu 2+ (938.5 eV) . Cu + /CuO and Cu 2+ existed in 500Cu-Z after Cu modified zeolite, and the peak near 935.2 eV disappeared in the XPS spectrum of 500Cu-Z/A/pulp after combustion, indicating that the Cu element in the zeolite exposed on the surface of the flame-retardant layer was mainly combined with the zeolite through coordination bonds.…”

Section: Resultsmentioning

confidence: 98%

“…The results confirm that Cu 2+ can be converted into Cu + under high-temperature calcination, which is consistent with the results of previous studies. 39 Surface Acidity Analysis of Zeolites. The surface acidity of the zeolite was analyzed by NH 3 -TPD.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…In Figure 7d, the Cu element mainly existed in ionic form, including Cu + (934.5 eV) and Cu 2+ (938.5 eV). 39 Cu + /CuO and Cu 2+ existed in 500Cu-Z after Cu modified zeolite, and the peak near 935.2 eV disappeared in the XPS spectrum of 500Cu-Z/A/pulp after combustion, indicating that the Cu element in the zeolite exposed on the surface of the flameretardant layer was mainly combined with the zeolite through During the combustion process, a thicker Si-containing flame-retardant layer formed after adding 500Cu-Z, which played the role of a flame retardant and smoke suppression. What is more, the 500Cu-Z catalyzed CO to CO 2 after coming in contact with CO gas through the Mars−van Krevelen mechanism.…”

Section: Acs Sustainablementioning

confidence: 99%

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Cu-Modified ZSM Zeolite Has Synergistic Flame Retardance, Smoke Suppression, and Catalytic Conversion Effects on Pulp Fiber After Ammonium Polyphosphate Flame-Retardant Treatment

Yang

Cai

Geng

et al. 2020

ACS Sustainable Chem. Eng.

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After the flame-retardant treatment, a pulp fiber has the problems of high smoke production and high smoke toxicity. To solve the above problems, a ZSM zeolite after copper modification was added to the ammonium polyphosphate (APP) flame-retardant pulp, and the effects of the modified ZSM zeolite on flame retardance, smoke suppression, and toxicity reduction were investigated. The content of Cu in the ZSM zeolite modified by ion exchange and calcination (500Cu-Z) was 1.73%, and its existing forms were free Cu 2+ , combined Cu 2+ , and Cu + . After modification, the strength of the weak and medium strong acids in the zeolite decreased, and the total acid content decreased by 10.90%. However, in the high-temperature range, a new strong acid site appeared. Compared with the APP-treated pulp fiber, the addition of 500Cu-Z could reduce the carbonization length, and the amount of smoke released decreased by 63.28% at the same time. The analysis of the gas composition indicates that the 500Cu-Z zeolite can reduce the relative concentration of CO to decrease the toxicity of smoke in the combustion process. A stronger flame-retardant layer was formed on the surface of the pulp fiber after adding zeolite and APP. There were chemical bonds such as PO, CC, C−O, Si−O−Si on the surface of the flame-retardant layer of 500Cu-Z/A/Pulp2.0. The 500Cu-Z zeolite had a synergistic flame-retardant effect with APP on the pulp fiber. After combustion, it was shown that a phosphoric acid layer existed on the surface of the fiber. The addition of zeolites can form a mosaic mechanism between the zeolite and the phosphoric acid layer to strengthen the flame-retardant layer. To conclude, the flameretardant layer may reduce the generation of smoke and 500Cu-Z zeolites in layer catalytic CO to CO 2 in smoke to reduce toxicity.

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Section: Resultssupporting

confidence: 93%