TY  - JOUR
AU  - Vennewald, Maurice
AU  - Sackers, Nina Michelle
AU  - Iemhoff, Andree
AU  - Kappel, Isabella
AU  - Weidenthaler, Claudia
AU  - Meise, Ansgar
AU  - Heggen, Marc
AU  - Dunin-Borkowski, Rafal
AU  - Keenan, Luke
AU  - Palkovits, Regina
TI  - Dynamics of palladium single-atoms on graphitic carbon nitride during ethylene hydrogenation
JO  - Journal of catalysis
VL  - 421
SN  - 0021-9517
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2023-01716
SP  - 134 - 144
PY  - 2023
AB  - Single-atoms on carbon–nitrogen supports are considered catalysts for a multitude of reactions. However, doubts remain whether really these species or subnanometer clusters formed under reaction conditions are the active species. In this work, we investigate the dynamics of palladium single-atoms on graphitic carbon nitride during ethylene hydrogenation and H2-D2 exchange. By employing aberration-corrected scanning transmission electron microscopy, x-ray photoelectron spectroscopy and x-ray absorption spectroscopy, we will show that palladium, originally present as single-atoms, agglomerates to clusters at 100 °C in a gas atmosphere that contains both ethylene and hydrogen. This agglomeration goes in hand with the emergence of catalytic activity in both ethylene hydrogenation and H2-D2 exchange, suggesting that clusters, rather than single-atoms, are the active species. The results presented herein highlight the potential of analytics over the course of reaction to identify the active species and provide new insights into the influence of gas atmosphere on metal speciation.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000956023800001
DO  - DOI:10.1016/j.jcat.2023.03.011
UR  - https://juser.fz-juelich.de/record/1006568
ER  -