Fundamental understanding of oxygen evolution reaction (OER) is of vital importance as it dominates the overall efficiency of water electrolysis - a compelling technique for sustainable production of ...hydrogen feedstock. Recently, a lattice oxygen-mediated mechanism (LOM) derived from lattice oxygen redox chemistry has received a lot of attention as it can rationalize the highly intrinsic activity and surface reconstruction issue in solid-state electrocatalyst alternatives with high metal-oxygen covalency. The physicochemical fundamentals of LOM further guide the exploration of efficient OER electrocatalysts. In this review, we comprehensively summarize the recent progress in lattice oxygen redox chemistry in solid-state OER electrocatalysts and its induced LOM. We begin with a brief introduction of LOM together with proposed pathways, and discuss the fundamental correlations between electronic structure of catalysts and OER mechanism to provide several electronic descriptors. Subsequently, we summarize the strategies for triggering lattice oxygen redox chemistry to promote the intrinsic OER activity, together with the theoretical calculations and experimental measurements for corroboration of lattice oxygen oxidation. Finally, we offer an outlook of the remaining challenges and future perspectives towards lattice oxygen redox chemistry in OER electrocatalysts. We anticipate that this review can inspire researchers to develop this attractive research area together.
Lattice oxygen redox chemistry in solid-state electrocatalysts rationalizes the remarkable OER activity by lattice oxygen-mediated mechanism. Here we elucidate the fundamental principle of this mechanism and summarize recently related developments.
Various quantum applications can be reduced to estimating expectation values, which are inevitably deviated by operational and environmental errors. Although errors can be tackled by quantum error ...correction, the overheads are far from being affordable for near-term technologies. To alleviate the detrimental effects of errors on the estimation of expectation values, quantum error mitigation techniques have been proposed, which require no additional qubit resources. Here we benchmark the performance of a quantum error mitigation technique based on probabilistic error cancellation in a trapped-ion system. Our results clearly show that effective gate fidelities exceed physical fidelities, i.e., we surpass the break-even point of eliminating gate errors, by programming quantum circuits. The error rates are effectively reduced from (1.10 ± 0.12) × 10
to (1.44 ± 5.28) × 10
and from (0.99 ± 0.06) × 10
to (0.96 ± 0.10) × 10
for single- and two-qubit gates, respectively. Our demonstration opens up the possibility of implementing high-fidelity computations on a near-term noisy quantum device.
A new and simple strategy towards electric‐field‐driven multiple chirality switching device has been designed and fabricated by combining a newly synthesized base‐responsive chiroptical polymer ...switch (R‐FLMA) and p‐benzoquinone (p‐BQ) via proton‐coupled electron transfer (PCET) mechanism. Clear and stable triple chirality states (silence, positive, negative) of this device in visible band can be regulated reversibly (>1000 cycles) by adjusting voltage programs. Furthermore, such chiral switching phenomena are also accompanied by apparent changes of color and fluorescence. More importantly, the potential application of this device for a spatial light modulator has also been demonstrated.
A simple and new strategy towards electric‐field‐driven multiple chirality switching material and device for spatial light modulators has been developed successfully based on the proton‐coupled electron transfer (PCET) mechanism.
Two semiconductive coordination polymers based on a chelating redox-active ligand were synthesized and structurally characterized. Strong and continuous intermolecular π-π interactions are likely the ...reason for moderate electrical conductivity of about 10
−5
S m
−1
in these materials. The results of DFT calculations indicate that the continuous π-π stacking structure contributes to the orbital overlap and thus improves charge transport performance.
Two layered semiconducting coordination polymers with chelating redox-active ligands were synthesized. Their moderate electrical conductivity is assigned to orbital overlap originating in continuous π-π interactions.
As a crucial indicator of modernization, urbanization has significant effects on carbon dioxide emissions. Using a panel data of 141 countries over the period of 1961–2011, this paper analyzes the ...impact of urbanization on carbon dioxide emissions empirically. We employ two-way fixed effects model based on the extended STIRPAT theoretical frameworks. Our results show that there is an inverted U-shaped relationship between urbanization and carbon emissions and the turn point is around 73.80%. But excessive urban concentration can claim the benefits of high-level urbanization. These findings can also help policy makers to use efficient urbanization to curb the carbon emissions, especially for the Asian countries that with high density of population.
•It uses a cross-country panel data of 141 countries over the period 1961–2011.•It employs two-way fixed effects model based on the extended STIRPAT framework.•There is inverted U-shaped relationship between urbanization and carbon emissions.•The turning point for OECD countries is 73.80% on urbanization.•Excessive urban concentration can claim the benefits of urban agglomeration.
This paper proposes the metafrontier non-radial Malmquist CO2 emission performance index (MNMCPI) for measuring dynamic changes in total-factor CO2 emission performance over time. The MNMCPI method ...allows for the incorporation of group heterogeneity and non-radial slack into the previously introduced Malmquist CO2 emission performance index (MCPI). We derive the MNMCPI by solving several non-radial data envelopment analysis (DEA) models. We decompose the MNMCPI into an efficiency change (EC) index, a best-practice gap change (BPC) index, and a technology gap change (TGC) index, and based on the proposed indices, we examine the dynamic changes in CO2 emission performance and its decomposition of fossil fuel power plants in China for the 2005–2010 period. The empirical results show a 0.38% increase in total-factor CO2 emission performance as a whole and a U-shaped MNMCPI curve for the sample period. Because companies owned by the central government lack innovation and technological leadership, the results suggest a missing link in the role of the central government in promoting CO2 emission performance.
•The metafrontier non-radial Malmquist CO2 emission performance index is proposed.•The dynamic changes in CO2 emission performance and its decomposition can be studied using the proposed model.•An empirical study of fossil fuel power plants in China are conducted for the 2005–2010 period.
Metal–organic frameworks with hydroxamate linkers are an emerging new class of stable porous crystalline materials. Due to the difficulty in controlling reversible formation of strong ...metal–hydroxamate bonds and the limitation of available hydroxamate ligands, hydroxamate MOFs are rarely reported and their applications are underexplored. Herein, we report on a lanthanum MOF, La-ONDI, containing the redox-active hydroxamate ligand ONDI 2− . Due to the presence of strong coordinative bonds of chelating hydroxamate groups to metal nodes, La-ONDI not only displays high framework stability in aqueous solutions ranging from pH 3 to pH 13, but also exhibits good structural integrity in common organic solvents and harsh reagents. In addition, La-ONDI shows paramagnetic behaviour due to the presence of unpaired electrons. The amount of unpaired electrons can be modified by the reducing environment during synthesis. Although without π–π interactions between neighbouring ligands, La-ONDI still exhibits good electrically conductive performance with the conductivity reaching 10 −6 S cm −1 .
Recently, a relatively new methodology named directional distance function (DDF) has been attracting positive attention in the field of energy and environmental (E&E) modeling. However, there is ...still no literature review on the application of DDF in E&E studies. This paper is intended to fill this gap. First, the most widely used DDF techniques and its extensions are briefly introduced. Second, this article attempts a classification of typical publications in this field. The main issues raised by the previous studies are discussed. Some guidelines for model selection and future directions are proposed for DDF related research in E&E studies.
•Total factor carbon emissions performance change for Chinese transportation sector is investigated.•The impact of regional heterogeneity is incorporated.•Metafrontier non-radial Luenberger carbon ...emission performance index is proposed.•Carbon emissions performance growth is mainly driven by technological innovation.
This study examines and decomposes dynamic changes in total factor carbon emissions performance within the transportation sector in China, incorporating the impact of regional heterogeneity. For this purpose, we combine the metafrontier approach with the non-radial Luenberger productivity indicator to propose a new definition named the metafrontier non-radial Luenberger carbon emission performance index (MNLCPI). This total factor index includes the efficiency change, best-practice gap change, and metafrontier technology gap change indexes. This method is capable of measuring dynamic changes in total factor carbon emissions performance over time via the production frontier framework and can incorporate group heterogeneity and non-radial slack into its measurement of total factor carbon emission performance. Empirical results applying this method show a 6.2% increase in overall total factor carbon emissions performance for the 2000–2012 period. This growth in carbon emissions performance is mainly driven by technological innovation, and different growth patterns are observed across China’s three main areas in transport sector.
In addition to carboxylate and N-donor linkers, hydroxamates are a kind of new emerging ligand to form coordination polymers. However, owing to the difficulty in controlling the reversible formation ...of strong metal-hydroxamate coordination bonds, reports on ditopic or multitopic hydroxamate coordination polymers are rare. In this work, we combined the ligand H
2
ONDI, a bis-hydroxamate with a naphthalenediimide (NDI) core and rigid chelating groups, with transition metal ions (Mn
2+
and Cd
2+
) and thus obtained three new hydroxamate coordination polymers. Benefiting from π-π stacking interactions between neighbouring ligands,
Mn-ONDI-1
and
CdCl-ONDI
show interesting electrical conductivities.
New coordination polymers based on a bis-hydroxamate linker, ONDI
2−
, exhibit semiconductive properties benefiting from their -π stacking structure.
PDF
