Nm-sized Particles Research Articles

Amorphous nickel nanophases inducing ferromagnetism in equiatomic Ni[sbnd]Ti alloy

Ni50Ti50 nm-sized amorphous particles are prepared using inert-gas condensation followed by in situ compaction. Elemental segregation of Ni and Ti is observed in the consolidated nanostructured material. Amorphous, nearly pure Nickel (96%) nanophases form within the amorphous Ni50Ti50 alloy. Combining atom probe tomography and scanning transmission electron microscopy with computer modelling, we explore the formation process of such amorphous nanophase structure. It is shown that the Ni rich amorphous phase in the consolidated nanostructured material is responsible for the ferromagnetic behavior of the sample whereas the rapidly quenched amorphous and crystalline samples with the same chemical composition (Ni50Ti50) were found to be paramagnetic. Due to the high cooling rate obtained using the inert gas condensation technique, an exceptional control over the crystallization processes is possible, promoting the formation of various amorphous phases, which are not obtained by standard rapid quenching techniques. Our findings demonstrate the potential of amorphous metallic nanostructures as advanced technological materials, and useful magnetic compounds.

Time- and Size-Resolved Plasmonic Evolution with nm Resolution of Galvanic Replacement Reaction in AuAg Nanoshells Synthesis

The rational design of advanced nanomaterials with enhanced optical properties can be reached only with the profound thermodynamic and kinetic understanding of their synthetic processes. In this work, the synthesis of monodisperse AuAg nanoshells with thin shells and large voids is achieved through the development of a highly reproducible and robust methodology based on the galvanic replacement reaction. This is obtained thanks to the systematic identification of the role played by the different synthetic parameters involved in the process (such as surfactants, co-oxidizers, complexing agents, time, and temperature), providing an unprecedented control over the material’s morphological and optical properties. Thus, the time- and size-resolved evolution of AuAg nanoshells surface plasmon resonance band is described for 15, 30, 60, 80, 100, and 150 nm-sized particles spanning almost through the entire visible spectrum. Its analysis reveals a four-phase mechanism coherent with the material’s morphological tra...

Size-dependent detection sensitivity of spherical particles sitting on a double-bent gold strip array

To achieve a size-dependent detection sensitivity of spherical nanoparticles, we propose a one-dimensional array of double-bent Au strips as a nanoplasmonic sensor and also as a size-filtering device. Electromagnetic simulations and measured absorbance spectra demonstrate that local plasmonic fields developed at the double-bent Au strips differentiate plasmonic responses for 100 nm- and 200 nm-sized spherical particles. Our results highlight the potential of the double-bent Au strip array as a sensing platform providing size-dependent sensitivity for spherical analytes.

Exploration of surface properties of Sb-promoted copper vanadate catalysts for selective catalytic reduction of NOX by NH3

A way to fulfill efficient exploitation of desired catalytic nature provided by V oxide is to modify its chemical structure through the incorporation of secondary transition metal species. This paper reports the use of Cu as a modifier of high-valent V oxide (V2O5) to produce a class of copper vanadates and their utilization as active sites for the selective catalytic reduction of NOX (X = 1 or 2) by NH3 (NH3-SCR). All catalysts contained ∼2 nm-sized copper vanadate particles highly dispersed on anatase with desired vanadate phases. The anatase-supported Cu5V2O10 provided a greater quantity of acid sites with improved redox character than Cu1V2O6, Cu2V2O7, and Cu3V2O8, thereby exhibiting the greatest NH3-SCR performance under ideal reaction conditions. Anatase-supported Cu3V2O8, however, was found to possess the most preferred surface properties among the catalysts post sulfation. This was evidenced by NH3-SCR runs of the catalysts under reaction conditions with H2O and SO2-including stream, where all catalysts were pre-sulfated by SO2 and O2 at elevated temperatures. The NH3-SCR performance of the optimum Cu3V2O8 on anatase was further promoted after sulfation of the catalyst with the optimum content of Sb promoter. The Sb promoter was verified to enhance the redox feature and minimize the interactions among catalyst surfaces and SO2/ammonium (bi)sulfates during the NH3-SCR, as evidenced by durability experiments. While showing N2 selectivities as ∼100% at ≤ 400 °C, the optimized Sb-promoted Cu3V2O8 on anatase showed high NOX conversions (≥ ∼85%) at ≥ 220 °C and outperformed the control vanadia-tungstate on anatase, which was used to simulate a commercial catalyst. This paper remarks the exploration of the variable structures of metal vanadates can be a good strategy to discover high-performance catalytic solids for the reduction of NOX species.

Controllable synthesis of SnO2@carbon hollow sphere based on bi-functional metallo-organic molecule for high-performance anode in Li-ion batteries

Constructing hollow structure and nano-sized SnO2 particles are two normal strategies to improve lithium storage performance of SnO2-based electrode. But it is still challengeable to fabricate ultrasmall SnO2 embedded in carbon hollow sphere in a controllable way. Herein, we have synthesized a kind of SnO2@carbon hollow sphere via a confined Friedel-Crafts crosslinking of a novel metal-organic compound (triphenyltin chloride, named Sn-Ph) on the surface of SiO2 template. The as-prepared SnO2@carbon hollow sphere has 10 nm-sized SnO2 particles embedded in amorphous carbon wall. Furthermore, 100, 200 and 400 nm-sized SnO2@carbon hollow spheres can be obtained by regulating the size of SiO2 template. When they are applied in lithium-ion batteries, the carbon structure can act as barriers to protect SnO2 particles from pulverization, and hollow core stores electrolyte and very small SnO2 particles of 10 nm shorten the diffusion distance of lithium ions. Thus, SnO2@carbon hollow sphere presents superior electrochemical performance. The first discharge and charge capacities reach 1378.5 and 507.3 mAh g−1 respectively, and 100 cycles later, its capacity remains 501.2 mAh g−1, indicating a capacity retention of 98.8% (C100th/C2nd).

Polymer-Templated LiFePO4/C Nanonetworks as High-Performance Cathode Materials for Lithium-Ion Batteries.

Lithium iron phosphate (LFP) is currently one of the main cathode materials used in lithium-ion batteries due to its safety, relatively low cost, and exceptional cycle life. To overcome its poor ionic and electrical conductivities, LFP is often nanostructured, and its surface is coated with conductive carbon (LFP/C). Here, we demonstrate a sol-gel based synthesis procedure that utilizes a block copolymer (BCP) as a templating agent and a homopolymer as an additional carbon source. The high-molecular-weight BCP produces self-assembled aggregates with the precursor-sol on the 10 nm scale, stabilizing the LFP structure during crystallization at high temperatures. This results in a LFP nanonetwork consisting of interconnected ∼10 nm-sized particles covered by a uniform carbon coating that displays a high rate performance and an excellent cycle life. Our "one-pot" method is facile and scalable for use in established battery production methodologies.

Interfacial Electrical Properties of Nanodiamond Colloidal Species in Aqueous Medium as Examined by Acid-Base Indicator Dyes

This study was aimed at further examining of a detonated nanodiamond hydrosol, produced by the NanoCarbon Research Institute, Japan. In the concentrated solution, this colloidal system consists mainly of 3 nm-sized primary particles. These particles are positively charged and tend to associate into larger colloidal species on dilution. The species adsorb, first of all, the anionic dyes and readily coagulate on adding electrolytes. Some properties of the sol are changed during prolonged ageing but may be restored by adding small HCl amounts. Besides measuring the electrokinetic potential, the interfacial electrical potential was estimated by using acid-base indicators.

Influence of SLM scan-speed on microstructure, precipitation of Al3Sc particles and mechanical properties in Sc- and Zr-modified Al-Mg alloys

Additive processing via Selective Laser Melting (SLM) of Sc- and Zr-modified Al-Mg alloys (commercially known as Scalmalloy®) provides significant advantages over traditional 4xxx casting alloys. This is due to the high strength and ductility at very low mechanical anisotropy, which is a result of the alloys' very fine-grained microstructure combined with weak texture in the build-up direction. Next to their advantageous mechanical properties, the reliability of alloys processed by additive manufacturing is of great importance. Variations in microstructural features due to the use of different in processing parameters (e.g. laser scan speed) are well known for traditional alloys. This study analyses the influence of varying laser scan speeds on the static mechanical properties of SLM-processed Scalmalloy®, and discusses the evolving microstructure and precipitation of nm-sized Al3Sc particles at the correspondingly different energy inputs. It is found that by about doubling the laser scan speed the peak grain sizes in the fine-grained regions decrease from 1.1μm to 600nm, whereas in the coarse grained region almost no influence is observed. Al3Sc particles are only precipitated during processing at low scan speeds due to the corresponding high laser energy input, or by the intrinsic heat treatment from subsequent layers being built.

Tin chemical shift anisotropy in tin dioxide: On ambiguity of CSA asymmetry derived from MAS spectra

Two different axial symmetries of the 119Sn chemical shift anisotropy (CSA) in tin dioxide with the asymmetry parameter (η) of 0 and 0.27 were reported previously based on the analysis of MAS NMR spectra. By analyzing the static powder pattern, we show that the 119Sn CSA is axially symmetric. A nearly axial symmetry and the principal axis system of the 119Sn chemical shift tensor in SnO2 were deduced from periodic scalar-relativistic density functional theory (DFT) calculations of NMR parameters. The implications of fast small-angle motions on CSA parameters were also considered, which could potentially lead to a CSA symmetry in disagreement with a crystal symmetry. Our analysis of experimental spectra using spectral simulations and iterative fittings showed that MAS spectra recorded at relatively high frequencies do not show sufficiently distinct features in order to distinguish CSAs with η ≈ 0 and η ≈ 0.4. The example of SnO2 shows that both the MAS lineshape and spinning sideband analyses may overestimate the η value by as much as ∼0.3 and ∼0.4, respectively. The results confirm that a static powder pattern must be analysed in order to improve the accuracy of the CSA asymmetry measurements. The measurements on SnO2 nanoparticles showed that the asymmetry parameter of the 119Sn CSA increases for nm-sized particles with a larger surface area compared to μm-sized particles. The increase of the η value for tin atoms near the surface in SnO2 was also confirmed by DFT calculations.

Nanoparticulate Impurities Isolated from Pharmaceutical-Grade Sucrose Are a Potential Threat to Protein Stability.

To investigate the effect of nanoparticulate impurities (NPIs) isolated from pharmaceutical-grade sucrose, on the stability of monoclonal antibodies (mAbs). NPIs were purified from pharmaceutical-grade sucrose and spiked into trastuzumab, rituximab, infliximab, and cetuximab formulations. The stability of the mAbs as a function of storage time, temperature, and NPI concentration was assessed by visual inspection, flow-imaging microscopy, nanoparticle tracking analysis, size-exclusion chromatography, capillary isoelectric focusing, and intrinsic differential scanning fluorimetry. NPIs negatively affected the stability of all mAbs, albeit it to different extents. After spiking with NPIs, trastuzumab formulations showed high numbers of μm-sized particles and turbidity, rituximab and cetuximab formulations contained high numbers of nm-sized particles, while infliximab formed nm- and μm-sized particles, and showed turbidity. Low-molecular-weight species were observed for rituximab and infliximab, whereas high-molecular-weight species were detected for cetuximab. Whereas the stability of trastuzumab and infliximab formulations was affected directly after spiking NPIs, degradation of rituximab and cetuximab was observed only after 14weeks at elevated temperatures. Moreover, the stability of rituximab and infliximab was affected by NPI concentrations that are potentially present in final drug products. The presence of sucrose-derived NPIs in (bio-)pharmaceutical formulations may pose a threat to the stability of mAbs.

Size-dependent genotoxicity of silver, gold and platinum nanoparticles studied using the mini-gel comet assay and micronucleus scoring with flow cytometry.

Metallic nanoparticles (NPs) are promising nanomaterials used in different technological solutions as well as in consumer products. Silver (Ag), gold (Au) and platinum (Pt) represent three metallic NPs with current or suggested use in different applications. Pt is also used as vehicle exhaust catalyst leading to a possible exposure via inhalation. Despite their use, there is limited data on their genotoxic potential and possible size-dependent effects, particularly for Pt NPs. The aim of this study was to explore size-dependent genotoxicity of these NPs (5 and 50 nm) following exposure of human bronchial epithelial cells. We characterised the NPs and assessed the viability (Alamar blue assay), formation of DNA strand breaks (mini-gel comet assay) and induction of micronucleus (MN) analysed using flow cytometry (in vitro microflow kit). The results confirmed the primary size (5 and 50 nm) but showed agglomeration of all NPs in the serum free medium used. Slight reduced cell viability (tested up to 50 µg/ml) was observed following exposure to the Ag NPs of both particle sizes as well as to the smallest (5 nm) Au NPs. Similarly, at non-cytotoxic concentrations, both 5 and 50 nm-sized Ag NPs, as well as 5 nm-sized Au NPs, increased DNA strand breaks whereas for Pt NPs only the 50 nm size caused a slight increase in DNA damage. No clear induction of MN was observed in any of the doses tested (up to 20 µg/ml). Taken together, by using the comet assay our study shows DNA strand breaks induced by Ag NPs, without any obvious differences in size, whereas effects from Au and Pt NPs were size-dependent in the sense that the 5 nm-sized Au NPs and 50 nm-sized Pt NPs particles were active. No clear induction of MN was observed for the NPs.

Self-Assembled Dendritic Pt Nanostructure with High-Index Facets as Highly Active and Durable Electrocatalyst for Oxygen Reduction.

The durability issues of Pt catalyst should be resolved for the commercialization of proton exchange membrane fuel cells. Nanocrystal structures with high-index facets have been recently explored to solve the critical durability problem of fuel cell catalysts as Pt catalysts with high-index facets can preserve the ordered surfaces without change of the original structures. However, it is very difficult to develop effective and practical synthetic methods for Pt-based nanostructures with high-index facets. The current study describes a simple one-pot synthesis of self-assembled dendritic Pt nanostructures with electrochemically active and stable high-index facets. Pt nanodendrites exhibited 2 times higher ORR activity and superior durability (only 3.0 % activity loss after 10 000 potential cycles) than a commercial Pt/C. The enhanced catalytic performance was elucidated by the formation of well-organized dendritic structures with plenty of reactive interfaces among 5 nm-sized Pt particles and the coexistence of low- and high-index facets on the particles.

Size-dependent structural and magnetic properties of chemically synthesized Co-Ni-Ga nanoparticles

Phase transitions and magnetic properties of shape-memory materials can be tailored by tuning the size of the constituent materials, such as nanoparticles. However, owing to the lack of suitable synthetic methods for size-controlled Heusler nanoparticles, there is no report on the size dependence of their properties and functionalities. In this contribution, we present the first chemical synthesis of size-selected Co-Ni-Ga Heusler nanoparticles. We also report the structure and magnetic properties of the biphasic Co-Ni-Ga nanoparticles with sizes in the range of 30–84 nm, prepared by a SBA-15 nanoporous silicatemplated approach. The particle sizes could be readily tuned by controlling the loading and concentration of the precursors. The fractions and crystallite sizes of each phase of the Co-Ni-Ga nanoparticles are closely related to their particle size. Enhanced magnetization and decreased coercivity are observed with increasing particle size. The Curie temperature (Tc) of the Co-Ni-Ga nanoparticles also depends on their size. The 84 nm-sized particles exhibit the highest Tc (≈ 1,174 K) among all known Heusler compounds. The very high Curie temperatures of the Co-Ni-Ga nanoparticles render them promising candidates for application in high-temperature shape memory alloy-based devices.

μm- and nm-Sized Catalytic Structures in Heat Sources for Thermoelectric Generators.

Micro- and nano-structural organization and its influence on the efficiency of catalysts used in the heat sources for permeable thermoelectric generators were investigated. Two types of catalyst were studied–elemental platinum on aluminum oxide granulate Pt/Al₂O₃ and mixed transition-metal catalyst on fibrous silicon dioxide Co–Cr–Pd–Sr/SiO₂. The distribution of active components in catalytic structures which contribute to the maximum combustion completeness of organic fuel in heat sources was investigated. Practically full conversion of hydrocarbons was achieved already with 1 mass.% of platinum in the Pt/Al₂O₃ catalyst with sub-μm- and nm-sized particles placed at the input of the gas-air mixture into the channel of the permeable thermoelement. The propane-butane conversion rate of 97% for the catalyst Co–Cr–Pd/SiO₂ with was further enhanced by addition of 0.5 mass.% of Sr. The catalytic centers are formed by CoCr₂O₄ nanocrystals (10 to 40 nm in size) with Pd promotor in form of single crystals on the fibrous SiO₂ matrix.

One Step Synthesis of Uniform SnO2 Electrode by UV Curing Technology toward Enhanced Lithium-Ion Storage.

A uniform anode material composed of ultrasmall tin oxide (SnO2) nanoparticles with an excellent lithium-ion (Li-ion) storage performance is obtained for the first time through one step UV curing technology. The diameter of ∼3 nm-sized SnO2 particles is uniformly dispersed in the styrylpyridinium (SbQ) polymer because of its photo-cross-linking property. The in situ cross-linking of SbQ polymer not only assist synthesis of uniform ultrasmall SnO2, but act as a strong adhesion binder on SnO2 nanoparticles, thereby effectively accommodating the volume expansion of SnO2 anodes during cycling process. The uniform electrode exhibits substantially higher specific capacity and longer cycling stability compared with the SnO2 nanoparticles electrodes treated by traditional PVDF-mixing method. A stable specific capacity of 572.5 mA h g-1 of the SnO2 electrode derived from UV curing technology is obtained at a current density of 0.2 C (156.2 mA g-1) after 150 cycles. Even at high rate of 5 C (3905 mA g-1), the electrode still demonstrates specific capacity of 440.2 mA h g-1. Therefore, the scalable and low-cost synthetic approach described herein can readily be extended to other nanomaterials electrodes to improve their lithium-storage properties.

Proton Conducting Nanocomposites Using Phosphonic Acid Grafted Polyhedral Oligomeric Silsesquioxane (POSS)

In PEMFC, nanocomposites are drawing attention as the alternative membrane because of selected various acid moiety functionalized additives, increased water retention and improved mechanical and thermal properties. But in modification of nanocomposites, when more than 100 nm-sized particles are introduced in ion channel, ion channel development is affected and hydrogen ion movement is reduced. So this study explores the concept of improving fuel cell membrane performance without compromising proton conductivity by using a 1 ~ 3 nm sized polyhedral oligomeric silsesquioxane (POSS). Polyhedral oligomeric silsesquioxane (POSS) is a molecule that has a spatially defined, rigid and hydrophobic cube-octameric siloxane skeleton (about 1 ~ 3 nm in size) with eight organic vertex groups, one or more of which are reactive or polymerizable. [1 ~ 3]. These particular structural features render POSS be a versatile additive for acquiring enhanced thermomechanical properties, better thermal stability, atom oxygen resistance, abrasion resistance and low water uptake [4 ~ 6]. Only one POSS-based nanocomposite for PEMFC h as been reported [7]. An open-cage POSS carrying three glycidyl epoxy groups was reacted with 4-hydroxybenzenesulfonic acid, the resulting sulfonated POSS was blended with polyvinylalcohol and the blend was crosslinked using ethylenediaminetetracetic dianhydride (EDTAD). This system differs considerably from the system described in this study (open-cage versus closed-cage POSS, crosslinked versus noncross-linked structure and aliphatic versus aromatic composition) and also has several disadvantages as follows: it requires a multistep fabrication process and it contains chemically unstable methylene groups. Additionally, the mechanical and chemical stability was not reported. In this study, POSS nanoadditives carrying phosphonic acid moieties were synthesized, characterized and formulated into Nafion®. As mention in the ref. [8 ~ 12], phosphonic acid groups are good candidate for high temperature proton carriers with the relatively high proton conductivity without water due to its self-dissociation natures. Also we developed Nafion®/3-aminopropyl triethoxysilane (APTES) hybrid membranes with phosphonic acid groups in the previous work in order to improved high temperature performances [11]. These hybrid membranes show high proton conductivities (0.028 S/cm) at 120 oC and 40% RH, so we can confirm the strong influence of phosphonic acid groups in low humid conditions. Also, in contrast to common additives, it can be possible to progressive improvement of proton conductivity because of eight vertex groups which substitute by phosphonic acid groups. We expect to innovatively improve proton conductivities by molecular-closed particle size and many vertex groups of POSS. The phosphonic acid grafted POSS prepared were characterized for particle size and chemical structure. Also Nafion®/POSS-PA nanocomposites were characterized for morphologies, mechanical strength, proton conductivities at different temperatures and humid conditions, and the cell performances at different temperatures.

Bandgap Energy of Wurtzite InAs Nanowires.

InAs nanowires (NWs) have been grown on semi-insulating InAs (111)B substrates by metal-organic chemical vapor deposition catalyzed by 50, 100, and 150 nm-sized Au particles. The pure wurtzite (WZ) phase of these NWs has been attested by high-resolution transmission electron microscopy and selected area diffraction pattern measurements. Low temperature photoluminescence measurements have provided unambiguous and robust evidence of a well resolved, isolated peak at 0.477 eV, namely 59 meV higher than the band gap of ZB InAs. The WZ nature of this energy band has been demonstrated by high values of the polarization degree, measured in ensembles of NWs both as-grown and mechanically transferred onto Si and GaAs substrates, in agreement with the polarization selection rules for WZ crystals. The value of 0.477 eV found here for the bandgap energy of WZ InAs agrees well with theoretical calculations.

Investigation of spark plasma sintered oxide-dispersion strengthened steels by means of small-angle neutron scattering

Spark plasma sintering (SPS) is an advanced consolidation technique, which particularly allows coarsening of the microstructure to be limited. The basis for the characteristics of the strengthening nanofeatures is already set in the milling process preceding SPS. The present study is focused on the dependence of the size distribution and nature of the nanofeatures in an ODS Fe-14Cr-1W-0.4Ti alloy as a function of the applied milling parameters and amount of added Y2O3 while keeping the SPS parameters constant. Statistically reliable averages of the particle characteristics representative of a macroscopic sample volume have been obtained by means of small-angle neutron scattering (SANS). The measured magnetic-to-nuclear scattering ratios have been critically compared to values calculated on the basis of structures and compositions reported in the literature. Milling parameters suitable to completely transform the added Y2O3 into Ti-containing nm-sized oxide particles have been identified. Two size ranges of particles have been analyzed separately: 0.5–3 nm and 3–15 nm (radius). The former size range is dominant in all ODS samples, the magnetic-to-nuclear scattering ratio indicates these particles to be predominantly Y2TiO5 and/or Y2Ti2O7.

Investigation on silicon alloying kinetics during lithiation by galvanostatic impedance spectroscopy

The parameters characterizing lithiation processes in silicon anodes of lithium ion batteries (LIBs) are compared between μm- and nm-sized silicon particles. Galvanostatic electrochemical impedance spectroscopy (GS-EIS) is used to investigate the silicon-lithium alloying reaction in a practical charging operation (galvanostatic lithiation). Effective kinetic parameters depending on lithiation C-rates are obtained along lithiation progress from a large body of impedance data. Nanosizing benefits of nanoparticles over micro-particles are confirmed such as lower polarization resistance (Rp) and thinner solid-electrolyte interphase layer (SEI layer) over the whole lithiation range. Based on the kinetic information obtained from the non-stationary conditions, a lithiation strategy consisting of multiple galvanostatic steps is designed to lithiate silicon anodes in a faster way. 75% of full capacity is lithiated by a galvanostatic sequence of 4C–2C–1C–0.5C within 20 min. However, only 43% and 21% are achieved by a single-rate galvanostatic lithiation at 1 C and 0.5 C, respectively.

Electrochemical Reduction of Carbon Dioxide to Ethane Using Nanostructured Cu2O-Derived Copper Catalyst and Palladium(II) Chloride

A method to facilitate the electrochemical reduction of carbon dioxide (CO2) to ethane (C2H6) was developed. The electrolyte used was aqueous 0.1 M KHCO3. Chronoamperometry, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, online gas chromatography, and nuclear magnetic resonance spectroscopy were used to characterize the electrochemical system and products formed. Carbon dioxide reduction using a Cu2O-derived copper working electrode gave ethylene (C2H4) and ethanol as main C2 products, with optimized faradic efficiencies (FE) of 32.1 and 16.4% at −1.0 V vs RHE. The active catalysts were ∼500 nm-sized crystalline Cu0 particles, which were formed via the reduction of the Cu2O precursor during the initial phase of the CO2 reduction reaction. When palladium(II) chloride was added to the electrolyte, C2H6 formation could be achieved with a significant FE of 30.1% at the said potential. The production of C2H4 was, on the other hand, suppressed to a FE of 3.4%. The alternate use of Pd0, PdO, or Pd–Al2O3 dopants did not afford the same conversion efficiency. Extensive mechanistic studies demonstrate that C2H4 was first produced from CO2 reduction at the Cu0 sites, followed by hydrogenation to C2H6 with the assistance of adsorbed PdClx. Interestingly, we discover that both Cu and PdClx sites are necessary for the efficient reduction of C2H4 to C2H6. The PdCl2 was “consumed” during the reaction, and a hypothesis for how it contributes to the reduction of CO2 to ethane is proposed.