Direct synthesis of H2O2 in AuPd coated micro channels: An in-situ X-Ray absorption spectroscopic study

Shamayita Kanungo, Lennart van Haandel, Emiel J.M. Hensen, Jaap C. Schouten, M. Fernanda Neira d'Angelo (Corresponding author)

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

6 Citaties (Scopus)
53 Downloads (Pure)

Uittreksel

For the first time, we perform in-situ X-Ray Absorption Spectroscopy on both Au L3 and Pd K edges during the direct synthesis of hydrogen peroxide in a high-pressure gas-liquid-solid microreactor using SiO2 supported Pd, Au and AuPd catalysts under relevant reaction conditions. The catalysts were coated on the walls of 320 µm ID micro capillaries, used in this work both as microreactors and as spectroscopic cells, ensuring safety of operation, ease of portability and absence of reactor effects during the measurements. XANES analysis revealed that the fresh Pd and AuPd catalysts contained a mix of Pd/PdO phases which was readily reduced in H2 atmosphere. The presence of only metallic Pd under reaction conditions for both catalysts proved that metallic Pd is the active phase for this reaction. Au was present in its metallic form in both Au and AuPd under all conditions tested. Unlike the AuPd, monometallic Pd showed an increase in the Pd-Pd distance under reaction conditions, attributed to the formation of Pd-hydride. We propose that the absence of Pd-hydride in the AuPd catalysts reduces further hydrogenation of H2O2 to water, thereby explaining the increased selectivity to H2O2 observed with AuPd catalysts.

Originele taal-2Engels
Pagina's (van-tot)200-209
Aantal pagina's10
TijdschriftJournal of Catalysis
Volume370
DOI's
StatusGepubliceerd - 1 feb 2019

Vingerafdruk

X ray absorption
catalysts
Catalysts
synthesis
x rays
Hydrides
hydrides
X ray absorption spectroscopy
Catalyst selectivity
hydrogen peroxide
Hydrogen peroxide
Hydrogen Peroxide
Hydrogenation
hydrogenation
safety
absorption spectroscopy
Gases
selectivity
reactors
atmospheres

Citeer dit

@article{39a96719830b46c8b78f06c92630e943,
title = "Direct synthesis of H2O2 in AuPd coated micro channels: An in-situ X-Ray absorption spectroscopic study",
abstract = "For the first time, we perform in-situ X-Ray Absorption Spectroscopy on both Au L3 and Pd K edges during the direct synthesis of hydrogen peroxide in a high-pressure gas-liquid-solid microreactor using SiO2 supported Pd, Au and AuPd catalysts under relevant reaction conditions. The catalysts were coated on the walls of 320 µm ID micro capillaries, used in this work both as microreactors and as spectroscopic cells, ensuring safety of operation, ease of portability and absence of reactor effects during the measurements. XANES analysis revealed that the fresh Pd and AuPd catalysts contained a mix of Pd/PdO phases which was readily reduced in H2 atmosphere. The presence of only metallic Pd under reaction conditions for both catalysts proved that metallic Pd is the active phase for this reaction. Au was present in its metallic form in both Au and AuPd under all conditions tested. Unlike the AuPd, monometallic Pd showed an increase in the Pd-Pd distance under reaction conditions, attributed to the formation of Pd-hydride. We propose that the absence of Pd-hydride in the AuPd catalysts reduces further hydrogenation of H2O2 to water, thereby explaining the increased selectivity to H2O2 observed with AuPd catalysts.",
keywords = "Au-Pd catalysts, Bimetallic catalysts, Direct synthesis, Hydrogen peroxide, In-situ/operando EXAFS, X-Ray absorption spectroscopy",
author = "Shamayita Kanungo and {van Haandel}, Lennart and Hensen, {Emiel J.M.} and Schouten, {Jaap C.} and {Neira d'Angelo}, {M. Fernanda}",
year = "2019",
month = "2",
day = "1",
doi = "10.1016/j.jcat.2018.12.017",
language = "English",
volume = "370",
pages = "200--209",
journal = "Journal of Catalysis",
issn = "0021-9517",
publisher = "Academic Press Inc.",

}

Direct synthesis of H2O2 in AuPd coated micro channels : An in-situ X-Ray absorption spectroscopic study. / Kanungo, Shamayita; van Haandel, Lennart; Hensen, Emiel J.M.; Schouten, Jaap C.; Neira d'Angelo, M. Fernanda (Corresponding author).

In: Journal of Catalysis, Vol. 370, 01.02.2019, blz. 200-209.

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

TY - JOUR

T1 - Direct synthesis of H2O2 in AuPd coated micro channels

T2 - An in-situ X-Ray absorption spectroscopic study

AU - Kanungo, Shamayita

AU - van Haandel, Lennart

AU - Hensen, Emiel J.M.

AU - Schouten, Jaap C.

AU - Neira d'Angelo, M. Fernanda

PY - 2019/2/1

Y1 - 2019/2/1

N2 - For the first time, we perform in-situ X-Ray Absorption Spectroscopy on both Au L3 and Pd K edges during the direct synthesis of hydrogen peroxide in a high-pressure gas-liquid-solid microreactor using SiO2 supported Pd, Au and AuPd catalysts under relevant reaction conditions. The catalysts were coated on the walls of 320 µm ID micro capillaries, used in this work both as microreactors and as spectroscopic cells, ensuring safety of operation, ease of portability and absence of reactor effects during the measurements. XANES analysis revealed that the fresh Pd and AuPd catalysts contained a mix of Pd/PdO phases which was readily reduced in H2 atmosphere. The presence of only metallic Pd under reaction conditions for both catalysts proved that metallic Pd is the active phase for this reaction. Au was present in its metallic form in both Au and AuPd under all conditions tested. Unlike the AuPd, monometallic Pd showed an increase in the Pd-Pd distance under reaction conditions, attributed to the formation of Pd-hydride. We propose that the absence of Pd-hydride in the AuPd catalysts reduces further hydrogenation of H2O2 to water, thereby explaining the increased selectivity to H2O2 observed with AuPd catalysts.

AB - For the first time, we perform in-situ X-Ray Absorption Spectroscopy on both Au L3 and Pd K edges during the direct synthesis of hydrogen peroxide in a high-pressure gas-liquid-solid microreactor using SiO2 supported Pd, Au and AuPd catalysts under relevant reaction conditions. The catalysts were coated on the walls of 320 µm ID micro capillaries, used in this work both as microreactors and as spectroscopic cells, ensuring safety of operation, ease of portability and absence of reactor effects during the measurements. XANES analysis revealed that the fresh Pd and AuPd catalysts contained a mix of Pd/PdO phases which was readily reduced in H2 atmosphere. The presence of only metallic Pd under reaction conditions for both catalysts proved that metallic Pd is the active phase for this reaction. Au was present in its metallic form in both Au and AuPd under all conditions tested. Unlike the AuPd, monometallic Pd showed an increase in the Pd-Pd distance under reaction conditions, attributed to the formation of Pd-hydride. We propose that the absence of Pd-hydride in the AuPd catalysts reduces further hydrogenation of H2O2 to water, thereby explaining the increased selectivity to H2O2 observed with AuPd catalysts.

KW - Au-Pd catalysts

KW - Bimetallic catalysts

KW - Direct synthesis

KW - Hydrogen peroxide

KW - In-situ/operando EXAFS

KW - X-Ray absorption spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85059345436&partnerID=8YFLogxK

U2 - 10.1016/j.jcat.2018.12.017

DO - 10.1016/j.jcat.2018.12.017

M3 - Article

AN - SCOPUS:85059345436

VL - 370

SP - 200

EP - 209

JO - Journal of Catalysis

JF - Journal of Catalysis

SN - 0021-9517

ER -