In situ DRIFTS investigation of the promoting effect of Zr on Pd/Al2O3 catalyst for the catalytic combustion of methane

2013 ◽  
Vol 111 (1) ◽  
pp. 137-148 ◽  
Author(s):  
Hongbo Na ◽  
Zhiming Liu ◽  
Tianle Zhu
Keyword(s):  
Catalytic Combustion ◽  
Promoting Effect ◽  
In Situ Drifts ◽  
Catalytic Combustion Of Methane ◽  
Al2o3 Catalyst

scholarly journals Glycerol Hydrogenolysis with In Situ Hydrogen Produced via Methanol Steam Reforming: The Promoting Effect of Pd on a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Promoting Effect ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Glycerol Dehydration ◽  
Effect Of Pd ◽  
Al2o3 Catalyst ◽  
Reaction Equilibrium

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.

scholarly journals Catalytic Combustion of Propane over Pt-Mo/ZSM-5 Catalyst: The Promotional Effects of Molybdenum

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1377
Author(s):  
Zhenan Liao ◽  
Kaiwen Zha ◽  
Wenjie Sun ◽  
Zhen Huang ◽  
Hualong Xu ◽  
...  
Keyword(s):  
Catalytic Combustion ◽  
Impregnation Method ◽  
Turnover Frequency ◽  
Propane Combustion ◽  
In Situ Drifts ◽  
Positive Correlation ◽  
Catalytic Stability ◽  
Molybdenum Doping

To improve propane combustion activity and illustrate the promotional effects of molybdenum doping, Pt-Mo/ZSM-5 catalysts with different Mo amounts were prepared by the co-impregnation method. XRD, Raman, H2-TPR, NH3-TPD, in situ DRIFTs, XPS and other characterizations were performed. The results indicated that the concentration of Pt0 in Pt/ZSM-5 catalyst increased after the doping of Mo and the content of Pt0 had a positive correlation with the reaction turnover frequency value. The propane combustion activity of Pt/ZSM-5 catalyst was significantly improved after the doping of molybdenum species. Among all the catalysts, Pt-6Mo/ZSM-5 catalyst (Pt/ZSM-5 with 6 wt.% Mo modification) showed the lowest T50 and T90 for propane catalytic combustion. Moreover, the Pt-Mo/ZSM-5 catalyst exhibited outstanding catalytic stability.

High-pressure catalytic combustion of methane over platinum: In situ experiments and detailed numerical predictions

2004 ◽  
Vol 136 (1-2) ◽  
pp. 217-240 ◽  
Author(s):  
Michael Reinke ◽  
John Mantzaras ◽  
Rolf Schaeren ◽  
Rolf Bombach ◽  
Andreas Inauen ◽  
...  
Keyword(s):  
High Pressure ◽  
Catalytic Combustion ◽  
Numerical Predictions ◽  
In Situ Experiments ◽  
Catalytic Combustion Of Methane

scholarly journals Promoting effect of Fe on supported Ni catalysts in CO2 methanation by in situ DRIFTS and DFT study

2020 ◽  
Vol 392 ◽  
pp. 266-277 ◽  
Author(s):  
Huong Lan Huynh ◽  
Jie Zhu ◽  
Guanghui Zhang ◽  
Yongli Shen ◽  
Wakshum Mekonnen Tucho ◽  
...  
Keyword(s):  
Dft Study ◽  
Promoting Effect ◽  
Ni Catalysts ◽  
Co2 Methanation ◽  
In Situ Drifts ◽  
Supported Ni Catalysts ◽  
Supported Ni

scholarly journals The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 412 ◽  
Author(s):  
Yuanqing Liu ◽  
Xiaoming Guo ◽  
Garry Rempel ◽  
Flora Ng
Keyword(s):  
Steam Reforming ◽  
Molecular Hydrogen ◽  
Biodiesel Production ◽  
Precipitation Method ◽  
Methanol Steam Reforming ◽  
Phase Reaction ◽  
Promoting Effect ◽  
High Hydrogen ◽  
Al2o3 Catalyst

Production of green chemicals using a biomass derived feedstock is of current interest. Among the processes, the hydrogenolysis of glycerol to 1,2-propanediol (1,2-PD) using externally supplied molecular hydrogen has been studied quite extensively. The utilization of methanol present in crude glycerol from biodiesel production can avoid the additional cost for molecular hydrogen storage and transportation, as well as reduce the safety risks due to the high hydrogen pressure operation. Recently the hydrogenolysis of glycerol with a Cu/ZnO/Al2O3 catalyst using in situ hydrogen generated from methanol steam reforming in a liquid phase reaction has been reported. This paper focusses on the effect of added Ni on the activity of a Cu/ZnO/Al2O3 catalyst prepared by an oxalate gel-co-precipitation method for the hydrogenolysis of glycerol using methanol as a hydrogen source. It is found that Ni reduces the conversion of glycerol but improves the selectivity to 1,2-PD, while a higher conversion of methanol is observed. The promoting effect of Ni on the selectivity to 1,2-PD is attributed to the slower dehydration of glycerol to acetol coupled with a higher availability of in situ hydrogen produced from methanol steam reforming and the higher hydrogenation activity of Ni towards the intermediate acetol to produce 1,2-PD.

scholarly journals An Investigation on the Promoting Effect of Pr Modification on SO2 Resistance Over MnOx Catalysts for Selective Reduction of NO with NH3

2021 ◽  
Author(s):  
Guangpeng Zhai ◽  
Zhitao Han ◽  
Huan Du ◽  
Yu Gao ◽  
Xinxiang Pan
Keyword(s):  
Active Sites ◽  
Manganese Oxides ◽  
Catalyst Surface ◽  
Selective Reduction ◽  
Future Application ◽  
Precipitation Process ◽  
Promoting Effect ◽  
In Situ Drifts ◽  
Co Precipitation

Abstract Manganese oxides (MnOx) exhibit excellent low-temperature activities in SCR reaction of NO with NH3, and they are considered as a promising catalyst for future application. However, MnOx still suffer from poor resistance to SO2 and H2O. In this work, Pr was used to modify MnOx catalysts via co-precipitation process, and MnPrOx catalyst exhibited superior SO2 resistance over pure MnOx catalyst. A series of characterization techniques, such as XRD, BET, H2-TPR, XPS, TG and in-situ DRIFTS, were adopted to explore the promoting effect of Pr modification on SO2 resistance over MnOx catalyst in detail. The results indicated that, in the presence of SO2 in feed gas, it seemed that PrOx rather than MnOx were apt to react with SO2, which was favorable to protect Mn active sites on the catalyst surface to some extent. It was known that there was strong competitive adsorption between SO2 and NH3/NO species on SCR catalyst surface. In-situ DRIFTS results revealed that the adsorption of NH3 and NO on MnOx catalyst had been severely suppressed after the introduction of SO2, resulting in the relevant SCR reactions following either L-H or E-R mechanisms would be inhibited obviously. But for Pr-modified MnOx catalyst, the introduction of SO2 almost had no effect on the adsorption of NH3 on catalyst surface, while it exerted a relatively noticeable impact on the adsorption of NO. As a result, SCR reactions occurred on Pr-modified MnOx catalyst surface could still proceed in a near-normal way through E-R rather than L-H mechanisms. Therefore, Pr modification on MnOx catalyst exhibited a distinctively promoting effect on SO2 resistance performance in SCR process.

scholarly journals Catalytic Combustion of Toluene over Highly Dispersed Cu-CeOx Derived from Cu-Ce-MOF by EDTA Grafting Method

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 519
Author(s):  
Wenjie Sun ◽  
Yijia Huang ◽  
Xiaomin Li ◽  
Zhen Huang ◽  
Hualong Xu ◽  
...  
Keyword(s):  
Catalytic Combustion ◽  
Oxygen Vacancies ◽  
Diffuse Reflectance ◽  
Ethylenediaminetetraacetic Acid ◽  
Deep Oxidation ◽  
In Situ Drifts ◽  
Metal Organic ◽  
Diffuse Reflectance Infrared ◽  
Key Steps

In this work, Cu-CeOx-MOF catalysts with well-dispersed Cu in different contents were synthesized via the ethylenediaminetetraacetic acid (EDTA) grafting method. EDTA was grafted in Ce-MOF-808 to anchor Cu and then the metal-organic frameworks (MOFs) were utilized as sacrificial template to form highly performed Cu-CeOx-MOF for toluene catalytic combustion. In this series of samples, Cu-CeOx-MOF-0.2 had a higher ratio of Oα/(Oα+Oβ), more oxygen vacancies and performed better low-temperature reducibility. Cu-CeOx-MOF-0.2 showed outstanding catalytic activity and stability. The T90 (temperature when toluene conversion achieved 90%) of Cu-CeOx-MOF-0.2 was 226 °C at 60,000 mL/(gcat∙h). In situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS) results revealed that the opening of aromatic ring and the deep oxidation of carboxylate were key steps for toluene catalytic combustion over Cu-CeOx-MOF-0.2.

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