3 research outputs found
Oxygen Vacancy Enhanced Proton Transfer to Boost Carbamate Decomposition Kinetics with Tunable Heterostructure Ni/NiO
Catalytic carbamate decomposition
is a feasible option for reducing
the heat duty of amine solvent regeneration during the chemisorption
of CO2 capture; advanced material with excellent proton
transfer and exchange performance is crucial to boost the decomposition
kinetics in an alkaline environment. Here, we prepared magnetic heterostructure
Ni/NiO nanocatalysts with tunable Ni(0) nanoparticles and NiO support.
The heterointerface of the proposed materials creates abundant surface
oxygen vacancies (OVs) and offers abundant reactive active sites ascribed
to the special electron transfer scheme of Ni0–NiO.
The generated surface hydroxyls and unsaturated coordinated Ni, respectively,
provide transferable protons and electrons, involved in the deprotonation
of RNH3+ and C–N break of RNHCOO–. Thus, the obtained nanomaterials achieved considerably
improved CO2 desorption of up to 3 mmol/min for a CO2-saturated monoethanolamine solvent, representing a substantial
(approximately 50%) increase over the catalyst-free case. The reinforcement
mechanism of OV generation by the Ni/NiO heterostructure and the induced
proton transfer were revealed through in situ spectroscopic measurement
and theoretical calculations. The results verified that the OVs stimulate
the production of surface hydroxyls and water-assisted proton hopping,
providing an advantageous condition for carbamate decomposition
Oxygen Vacancy Enhanced Proton Transfer to Boost Carbamate Decomposition Kinetics with Tunable Heterostructure Ni/NiO
Catalytic carbamate decomposition
is a feasible option for reducing
the heat duty of amine solvent regeneration during the chemisorption
of CO2 capture; advanced material with excellent proton
transfer and exchange performance is crucial to boost the decomposition
kinetics in an alkaline environment. Here, we prepared magnetic heterostructure
Ni/NiO nanocatalysts with tunable Ni(0) nanoparticles and NiO support.
The heterointerface of the proposed materials creates abundant surface
oxygen vacancies (OVs) and offers abundant reactive active sites ascribed
to the special electron transfer scheme of Ni0–NiO.
The generated surface hydroxyls and unsaturated coordinated Ni, respectively,
provide transferable protons and electrons, involved in the deprotonation
of RNH3+ and C–N break of RNHCOO–. Thus, the obtained nanomaterials achieved considerably
improved CO2 desorption of up to 3 mmol/min for a CO2-saturated monoethanolamine solvent, representing a substantial
(approximately 50%) increase over the catalyst-free case. The reinforcement
mechanism of OV generation by the Ni/NiO heterostructure and the induced
proton transfer were revealed through in situ spectroscopic measurement
and theoretical calculations. The results verified that the OVs stimulate
the production of surface hydroxyls and water-assisted proton hopping,
providing an advantageous condition for carbamate decomposition
Sulfur Migration Enhanced Proton-Coupled Electron Transfer for Efficient CO<sub>2</sub> Desorption with Core-Shelled C@Mn<sub>3</sub>O<sub>4</sub>
Transforming
hazardous species into active sites by ingenious material
design was a promising and positive strategy to improve catalytic
reactions in industrial applications. To synergistically address the
issue of sluggish CO2 desorption kinetics and SO2-poisoning solvent of amine scrubbing, we propose a novel method
for preparing a high-performance core–shell C@Mn3O4 catalyst for heterogeneous sulfur migration and in
situ reconstruction to active –SO3H groups, and
thus inducing an enhanced proton-coupled electron transfer (PCET)
effect for CO2 desorption. As anticipated, the rate of
CO2 desorption increases significantly, by 255%, when SO2 is introduced. On a bench scale, dynamic CO2 capture
experiments reveal that the catalytic regeneration heat duty of SO2-poisoned solvent experiences a 32% reduction compared to
the blank case, while the durability of the catalyst is confirmed.
Thus, the enhanced PCET of C@Mn3O4, facilitated
by sulfur migration and simultaneous transformation, effectively improves
the SO2 resistance and regeneration efficiency of amine
solvents, providing a novel route for pursuing cost-effective CO2 capture with an amine solvent