TY - JOUR
T1 - Mechanistic Insights into Photocatalyzed Hydrogen Desorption from Palladium Surfaces Assisted by Localized Surface Plasmon Resonances
AU - Spata, Vincent A.
AU - Carter, Emily A.
N1 - Funding Information:
V.A.S. gratefully acknowledges current and former group members, respectively, Dr. John Mark Martirez and Dr. Caroline Krauter, for their assistance and guidance with the calculations and for useful discussions. V.A.S. also thanks Dr. Martirez, Dr. Qi Ou, Dr. Johannes M. Dieterich, and Ms. Nari L. Baughman for their editing help. E.A.C. acknowledges financial support from the Air Force Office of Scientific Research via the Department of Defense Multidisciplinary University Research Initiative, under Award FA9550-15-1-0022. The High Performance Computing Modernization Program (HPCMP) of the U.S. Department of Defense and Princeton University’s Terascale Infrastructure for Groundbreaking Research in Engineering and Science (TIGRESS) provided the computational resources.
PY - 2018/4/24
Y1 - 2018/4/24
N2 - Nanoparticles synthesized from plasmonic metals can absorb low-energy light, producing an oscillation/excitation of their valence electron density that can be utilized in chemical conversions. For example, heterogeneous photocatalysis can be achieved within heterometallic antenna-reactor complexes (HMARCs), by coupling a reactive center at which a chemical reaction occurs to a plasmonic nanoparticle that acts as a light-absorbing antenna. For example, HMARCs composed of aluminum antennae and palladium (Pd) reactive centers have been demonstrated recently to catalyze selective hydrogenation of acetylene to ethylene. Here, we explore within a theoretical framework the rate-limiting step of hydrogen photodesorption from a Pd surface - crucial to achieving partial rather than full hydrogenation of acetylene - to understand the mechanism behind the photodesorption process within the HMARC assembly. To properly describe electronic excited states of the metal-molecule system, we employ embedded complete active space self-consistent field and n-electron valence state perturbation theory to second order within density functional embedding theory. The results of these calculations reveal that the photodesorption mechanism does not create a frequently invoked transient negative ion species but instead enhances population of available excited-state, low-barrier pathways that exhibit negligible charge-transfer character.
AB - Nanoparticles synthesized from plasmonic metals can absorb low-energy light, producing an oscillation/excitation of their valence electron density that can be utilized in chemical conversions. For example, heterogeneous photocatalysis can be achieved within heterometallic antenna-reactor complexes (HMARCs), by coupling a reactive center at which a chemical reaction occurs to a plasmonic nanoparticle that acts as a light-absorbing antenna. For example, HMARCs composed of aluminum antennae and palladium (Pd) reactive centers have been demonstrated recently to catalyze selective hydrogenation of acetylene to ethylene. Here, we explore within a theoretical framework the rate-limiting step of hydrogen photodesorption from a Pd surface - crucial to achieving partial rather than full hydrogenation of acetylene - to understand the mechanism behind the photodesorption process within the HMARC assembly. To properly describe electronic excited states of the metal-molecule system, we employ embedded complete active space self-consistent field and n-electron valence state perturbation theory to second order within density functional embedding theory. The results of these calculations reveal that the photodesorption mechanism does not create a frequently invoked transient negative ion species but instead enhances population of available excited-state, low-barrier pathways that exhibit negligible charge-transfer character.
KW - acetylene hydrogenation
KW - composite nanostructures
KW - heterogeneous catalysis
KW - heterometallic antenna-reactor complex
KW - hydrogen dissociation
KW - localized surface plasmon resonance
KW - transition metal catalysts
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U2 - 10.1021/acsnano.8b00352
DO - 10.1021/acsnano.8b00352
M3 - Article
C2 - 29558105
AN - SCOPUS:85045832871
SN - 1936-0851
VL - 12
SP - 3512
EP - 3522
JO - ACS Nano
JF - ACS Nano
IS - 4
ER -