Characterization and catalytic performance of a bimetallic Pt–Sn/HZSM-5 catalyst used in denitratation of drinking water

Rodríguez, Rafael; Pfaff, C. H.; Melo, Luis; Betancourt, Paulino

doi:10.1016/j.cattod.2005.07.070

Cited by 21 publications

(5 citation statements)

References 52 publications

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“…However, monometallic palladium catalysts (Pd/support) are active only in the reduction of nitrates(III). Some researchers explain the low activity of Pd/support catalysts in comparison with bimetallic Pd-M/support systems in the reduction of nitrates(V) by different mechanisms of these processes such as a redox, and a catalytic mechanisms [3][4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Temperature-programmed desoprtion of H2 from the surfaces of pd/support and Pd-Ag/support catalysts (support = Al2O3, SiO2)

Witońska

Karski

Frajtak

et al. 2008

React Kinet Catal Lett

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Thermal desorption of H 2 from the surface of Pd/support and Pd-Ag/support (support = Al 2 O 3 , SiO 2 ) catalysts has been investigated. Two wide desorption peaks can be observed for the 5%Pd/support catalyst. The presence of these peaks in the thermogram indicates that several adsorption states exist, which is the result of occurrance of different adsorption centers of specific bond strengths for hydrogen. The addition of silver to the palladium catalysts causes a considerable decrease in the size of the high temperature desorption peak. It is also worth noting that the temperature of the maximum of the desorption rate remains practically constant for all bimetallic catalysts studied. This means that the activation energy of the hydrogen desorption process does not change after the introduction of silver to the palladium catalyst.

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Section: Introductionmentioning

confidence: 99%

Temperature-programmed desoprtion of H2 from the surfaces of pd/support and Pd-Ag/support catalysts (support = Al2O3, SiO2)

Witońska

Karski

Frajtak

et al. 2008

React Kinet Catal Lett

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“…For Pt − Sn/Al 2 O 3 catalysts prepared by a so-called ''catalytic reduction'' method, TPR in conjunction with activity measurements for cyclohexane dehydrogenation showed that a large amount of tin was deposited on or close to the active metallic phase [76]. For a Pt − Sn/HZSM-5 catalyst a tin surface enrichment, the formation of PtSn alloys and platinum catalysis of the tin reduction were reported [78]. Surface enrichment in tin and the presence of tin stabilized on the support, probably as Sn 2+ /Sn 4+ oxides, was also observed.…”

Section: Bimetallic Systemsmentioning

confidence: 99%

Temperature‐Programmed Reduction and Oxidation1A list of symbols used in the text is provided at the end of the chapter.

Knözinger

2008

Handbook of Heterogeneous Catalysis

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The sections in this article are Introduction The TPR Experiment Kinetics and Mechanism of Reduction Mathematical Treatment of TPR Profiles and Influence of Experimental Parameters Examples Conclusion

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“…질산성 질소 저감 반응용 촉매는 단일 금속보다 이중 금속 (귀금속-비귀금속) 담지 촉매가 높은 활성을 보였다 [12][13][14]. 귀 금속은 팔라듐과 백금이 주로 사용되었고, 구리, 인듐, 주석 등이 비귀금속으로 적용되었다 [15][16][17][18]. 이 중, 팔라듐-구리가 담지된 촉매가 가장 우수한 성능을 나타내는 것으로 보고되고 있다 [19][20][21].…”

Section: No3 -+ H2 → No2 -+ H2ounclassified

Catalytic Nitrate Reduction in Water over Mesoporous Silica Supported Pd-Cu Catalysts

Kim¹,

Chung²,

Lee³

et al. 2013

Clean Technology

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요 약 본 연구에서는 중형 기공성 실리카 담체인 MCM-41과 SBA-15를 활용하여 팔라듐과 구리를 담지한 후, 제조 촉매의 수중 질 산성 질소 저감 반응 활성을 평가하였다. 순수 수소 공급 반응 조건에서, 질산성 질소의 농도는 반응 시간에 따라 점차 저감 되었지만, 반응기 내부에 높게 형성된 pH로 인해 질소의 선택도가 매우 낮은 문제점이 발견되었다. 이를 해결하기 위해 이 산화탄소를 수소와 함께 공급하여 pH의 안정화를 도모하였고, 질소 선택도를 40% 가량 증가시켰다. 상기 두 반응 조건에서 모두 Pd-Cu/MCM-41가 Pd-Cu/SBA-15보다 높은 활성을 나타냈다. 이와 같이 수중 질산성 질소 저감 반응의 활성에 차이를 보이는 두 촉매에 대하여, 질소 흡-탈착, XRD, H2-TPR, XPS 등과 같은 특성 분석을 수행하여 제조 촉매의 구조와 물성이 반 응활성에 미치는 영향을 검토해보았다.주제어 : 질산성 질소 저감 반응, Pd-Cu/MCM-41, Pd-Cu/SBA-15, 물 Abstract : In this study, we investigated the activity of Pd and Cu co-incorporated on mesoporous silica support such as MCM-41 and SBA-15 for catalytic nitrate reduction in water. In pure hydrogen flow, nitrate concentration was gradually decreased with the reaction time, but nitrogen selectivity was too low due to very high pH of reaction medium after the reaction. In order to acquire high nitrogen selectivity, we utilized carbon dioxide as a pH buffer, which resulted in higher nitrogen selectivity (about 40%). For the above reaction conditions, Pd-Cu/MCM-41 showed better performance than Pd-Cu/SBA-15. The physicochemical properties of both catalysts were investigated to figure out the relationship between the characteristics of the catalysts and the catalytic activity on the catalytic nitrate reduction by N2 adsoprtion-desorption, X-ray diffraction (XRD), H2-temperature programmed reduction, X-ray photoelectron spectroscopy (XPS) techniques.

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Characterization and catalytic performance of a bimetallic Pt–Sn/HZSM-5 catalyst used in denitratation of drinking water

Cited by 21 publications

References 52 publications

Temperature-programmed desoprtion of H2 from the surfaces of pd/support and Pd-Ag/support catalysts (support = Al2O3, SiO2)

Temperature-programmed desoprtion of H2 from the surfaces of pd/support and Pd-Ag/support catalysts (support = Al2O3, SiO2)

Temperature‐Programmed Reduction and Oxidation1A list of symbols used in the text is provided at the end of the chapter.

Catalytic Nitrate Reduction in Water over Mesoporous Silica Supported Pd-Cu Catalysts

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