| 1. |
- Osadchuk, Irina, et al.
(författare)
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Reduced State of Iridium PCP Pincer Complexes in Electrochemical CO2 Hydrogenation
- 2016
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 6:6, s. 3834-3839
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Tidskriftsartikel (refereegranskat)abstract
- We present a computational study on the mechanism for electrochemical reduction of CO2 using a PCP pincer iridium(III) dihydride complex. Our results point toward a mechanism that involves an in situ-generated iridium(I) hydride as the active species for the CO2 to formate reduction. The iridium(III) path can operate in parallel but is associated with higher activation free energies in the reaction between the metal hydride and CO2, compared to the reaction at the in situ-generated iridium(I) species.
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| 2. |
- Osadchuk, Irina, et al.
(författare)
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Theoretical Investigation of a Parallel Catalytic Cycle in CO2 Hydrogenation by (PNP)IrH3
- 2015
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Ingår i: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 34:20, s. 4932-4940
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Tidskriftsartikel (refereegranskat)abstract
- The (PNP)IrH3 (2,6-bis(diisopropylphosp-hinomethyl)pyridine iridium trihydride) complex by Nozaki is a highly active and selective catalyst for CO2 hydrogenation to formic acid in aqueous KOH. Previous theoretical investigations found that regeneration of the catalyst is the rate-determining step in this reaction. In the current article we present results from a computational study using density func- theory in order to consider the possibility of sequential insertion of two CO2 molecules in two Ir-H bonds before the reaction with hydrogen. We found that insertion of a second CO2 molecule is indeed possible; moreover, this sequential insertion allows formation of a more electrophilic iridium mono-hydride intermediate, and thereby the process of H-2 cleavage is facilitated. In addition, we considered the influence of ligands coplanar with the PNP ligand on the energy of CO2 insertion into the (PNP)IrH2X complex and found that sigma- and pi-donating ligands promote the reaction.
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| 3. |
- Pehme, Kaur-Mikk, et al.
(författare)
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Urban hydrology research fundamentals for waste management practices
- 2019
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Ingår i: 25<sup>th</sup> Annual International Scientific Conference "Research for Rural Development 2019" 15 - 17 May, 2019, vol 1. - Jelgava : Latvia University of Life Sciences and Technologies. ; , s. 160-167
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Konferensbidrag (refereegranskat)abstract
- The urbanization and increasing growth of planet’s population accumulates significant volume of disposed wasteas well as increases risks on human health and environmental safety. Landfill systems are the dynamic, livingin space and time, potentially harmful entities that must be managed in as careful and smart way as possible.There are many studies related to landfill emissions such as leachates and methane. However, there is a need foradvanced understanding of landfill hydrological regime and risks related to climate change and associated changesof hydrological cycle. The comprehensive studies about the urban hydrology are available; however, applicationto landfill management is fragmentary and inconsistent in several aspects. Landfill in long term has an impact onhydrological cycle. The heterogeneous land surface is one of aspects; however, there are still unanswered questionsabout the urban environment impact on water balance components. The aim of this study is to describe fundamentalsof landfill hydrology in urban hydrological response unit context as well as evaluate the potential risks to environmentand human health related to landfill geomorphology and hydrological balance in temporal climate conditions. Thelandfill hydrological cycle has similarities with urban hydrological cycle; however, there are additional componentsrelated to landfill specification, e.g., irrigation or leachate recirculation as well as total produced leachate.
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