AgPd and CuPd Catalysts for Selective Hydrogenation of Acetylene
Abstract not provided
36 MATERIALS SCIENCE↗
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Semi-grand canonical Monte Carlo simulation of the acrolein induced surface segregation and aggregation of AgPd with machine learning surrogate models
The single atom alloy of AgPd has been found to be a promising catalyst for the selective hydrogenation of acrolein. It is also known that the formation of Pd islands on the surface will greatly reduce the selectivity of the reaction. As a result, the surface segregation and aggregation of Pd on the AgPd surface under reaction conditions of selective hydrogenation of acrolein are of great interest. In this work, we lay out a workflow that can predict the surface segregation and aggregation of Pd on a FCC(111) AgPd surface with and without the presence of acrolein. We use machine learning surrogate models to predict the AgPd bulk energy, AgPd slab energy, and acrolein adsorption energy on AgPd slabs. Then, we use the semi-grand canonical Monte Carlo simulation to predict the surface segregation and aggregation under different bulk Pd concentrations. Under vacuum conditions, our method predicts that only trace amount of Pd will exist on the surface at Pd bulk concentrations less than 20%. However, with the presence of acrolein, Pd will start to aggregate as dimers on the surface at Pd bulk concentrations as low as 6.5%.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Investigation on the AgPt and AgPd hybrid alloy nanoparticles (HANPs) for the hybrid MoS 2 /ZnO/HANP UV photodetector application
We report hybrid photodetectors made of two or more nanomaterial components can offer the high potential for advanced photodetection applications with enhanced light absorption, improved efficiency and structural tunability. A hybrid UV photodetector (PD) configuration incorporating the plasmonic hybrid alloy nanoparticles (HANP), ZnO quantum dots (QDs) and MoS 2 nanoflakes, namely MoS2/ZnO/HANP PD, is demonstrated. The optimized MoS 2 /ZnO/HANP PD exhibits a high photocurrent of 5.66 mA at 0.34 mW/mm 2 under 385 nm illumination with two orders of improvement from the bare ZnO, which is one of the highest photocurrents by the ZnO-based PDs. It also demonstrates high figure-of-merits with the responsivity of 14,523 mA/W, detectivity of 8.13 x 10 11 jones, and external quantum efficiency (EQE) of 4,680 %, outperforming most of the ZnO-based hybrid architectures. The enhanced photoresponse is primarily attributed to the significantly enhanced hot electron generation by the AgPd HANPs and photocarrier collection through the ZnO QD layer. MoS 2 nanoflakes also provide additional photon absorption sites and boost the photo-carrier transfer process. HANPs are grown by adapting a dual-step solid-state dewetting process (SSD) approach and the superiority of AgPd HANPs is confirmed by systematic investigation, FDTD simulation and comparison of AgPt and AgPd HANPs.
MoS2↗
Materials Data on AgPd by Materials Project
PdAg crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded to six equivalent Pd and six Ag atoms to form PdAg6Pd6 cuboctahedra that share corners with twelve PdAg6Pd6 cuboctahedra, edges with twelve PdAg6Pd6 cuboctahedra, edges with twelve AgAg6Pd6 cuboctahedra, faces with six equivalent PdAg6Pd6 cuboctahedra, and faces with twelve AgAg6Pd6 cuboctahedra. All Pd–Pd bond lengths are 2.87 Å. All Pd–Ag bond lengths are 2.86 Å. In the second Pd site, Pd is bonded to ten equivalent Pd and six Ag atoms to form PdAg6Pd10 cuboctahedra that share corners with ten AgAg6Pd6 cuboctahedra, corners with twelve PdAg6Pd6 cuboctahedra, edges with eight AgAg6Pd6 cuboctahedra, edges with sixteen PdAg6Pd6 cuboctahedra, faces with sixteen equivalent PdAg6Pd10 cuboctahedra, and faces with eighteen AgAg6Pd6 cuboctahedra. There are a spread of Pd–Pd bond distances ranging from 2.87–5.74 Å. All Pd–Ag bond lengths are 2.86 Å. There are three inequivalent Ag sites. In the first Ag site, Ag is bonded to six equivalent Pd and six equivalent Ag atoms to form AgAg6Pd6 cuboctahedra that share corners with twelve AgAg6Pd6 cuboctahedra, edges with twelve equivalent PdAg6Pd6 cuboctahedra, edges with twelve AgAg6Pd6 cuboctahedra, faces with six equivalent AgAg6Pd6 cuboctahedra, and faces with twelve equivalent PdAg6Pd6 cuboctahedra. All Ag–Ag bond lengths are 2.87 Å. In the second Ag site, Ag is bonded to six Pd and six equivalent Ag atoms to form AgAg6Pd6 cuboctahedra that share corners with five equivalent PdAg6Pd10 cuboctahedra, corners with twelve AgAg6Pd6 cuboctahedra, edges with ten PdAg6Pd6 cuboctahedra, edges with twelve AgAg6Pd6 cuboctahedra, faces with six equivalent AgAg6Pd6 cuboctahedra, and faces with fifteen PdAg6Pd6 cuboctahedra. All Ag–Pd bond lengths are 2.86 Å. All Ag–Ag bond lengths are 2.87 Å. In the third Ag site, Ag is bonded to six Pd and six equivalent Ag atoms to form AgAg6Pd6 cuboctahedra that share corners with five equivalent PdAg6Pd10 cuboctahedra, corners with twelve AgAg6Pd6 cuboctahedra, edges with ten PdAg6Pd6 cuboctahedra, edges with twelve AgAg6Pd6 cuboctahedra, faces with six equivalent AgAg6Pd6 cuboctahedra, and faces with fifteen PdAg6Pd6 cuboctahedra. All Ag–Ag bond lengths are 2.87 Å.
36 MATERIALS SCIENCE↗
Materials Data on AgPd by Materials Project
PdAg crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Pd is bonded to six equivalent Pd and six equivalent Ag atoms to form PdAg6Pd6 cuboctahedra that share corners with eighteen equivalent PdAg6Pd6 cuboctahedra, edges with six equivalent PdAg6Pd6 cuboctahedra, edges with twelve equivalent AgAg6Pd6 cuboctahedra, faces with eight equivalent PdAg6Pd6 cuboctahedra, and faces with twelve equivalent AgAg6Pd6 cuboctahedra. All Pd–Pd bond lengths are 2.86 Å. All Pd–Ag bond lengths are 2.87 Å. Ag is bonded to six equivalent Pd and six equivalent Ag atoms to form AgAg6Pd6 cuboctahedra that share corners with eighteen equivalent AgAg6Pd6 cuboctahedra, edges with six equivalent AgAg6Pd6 cuboctahedra, edges with twelve equivalent PdAg6Pd6 cuboctahedra, faces with eight equivalent AgAg6Pd6 cuboctahedra, and faces with twelve equivalent PdAg6Pd6 cuboctahedra. All Ag–Ag bond lengths are 2.86 Å.
36 MATERIALS SCIENCE↗
Lattice-Resolution, Dynamic Imaging of Hydrogen Absorption into Bimetallic AgPd Nanoparticles
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
AgPd nanoparticles for electrocatalytic CO 2 reduction: bimetallic composition-dependent ligand and ensemble effects
By balancing bimetallic composition-associated ligand and ensemble effects, Ag 15 Pd 85 nanoparticles show enhanced catalytic properties for electrochemical CO 2 reduction.
25 ENERGY STORAGE↗
Controlling Selectivity in Plasmonic Catalysis: Switching Reaction Pathway from Hydrogenation to Homocoupling Under Visible‐Light Irradiation
Abstract Plasmonic catalysis enables the use of light to accelerate molecular transformations. Its application to the control reaction selectivity is highly attractive but remains challenging. Here, we have found that the plasmonic properties in AgPd nanoparticles allowed different reaction pathways for tunable product formation under visible‐light irradiation. By employing the hydrogenation of phenylacetylene as a model transformation, we demonstrate that visible‐light irradiation can be employed to steer the reaction pathway from hydrogenation to homocoupling. Our data showed that the decrease in the concentration of H species at the surface due to plasmon‐enhanced H 2 desorption led to the control in selectivity. These results provide important insights into the understanding of reaction selectivity with light, paving the way for the application of plasmonic catalysis to the synthesis of 1,3‐diynes, and bringing the vision of light‐driven transformations with target selectivity one step closer to reality.
Peiris, Erandi↗
Controlling Selectivity in Plasmonic Catalysis: Switching Reaction Pathway from Hydrogenation to Homocoupling Under Visible–Light Irradiation
Plasmonic catalysis enables the use of light to accelerate molecular transformations. Its application to the control reaction selectivity is highly attractive but remains challenging. Here, we have found that the plasmonic properties in AgPd nanoparticles allowed different reaction pathways for tunable product formation under visible-light irradiation. By employing the hydrogenation of phenylacetylene as a model transformation, we demonstrate that visible-light irradiation can be employed to steer the reaction pathway from hydrogenation to homocoupling. Our data showed that the decrease in the concentration of H species at the surface due to plasmon-enhanced H2 desorption led to the control in selectivity. Furthermore, these results provide important insights into the understanding of reaction selectivity with light, paving the way for the application of plasmonic catalysis to the synthesis of 1,3-diynes, and bringing the vision of light-driven transformations with target selectivity one step closer to reality.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Efficient Screening of Bi–Metallic Electrocatalysts for Glycerol Valorization
Glycerol is a byproduct of biodiesel production and, as such, it is of limited economic value. By means of electrooxidation, glycerol can be used as a feedstock for scalable hydrogen production, in addition to conversion to value-added products. The development of novel and efficient catalytic electrode materials for the anodic side of the reaction is a key towards a hydrogen-based energy economy. In the present study, a computational screening protocol combining DFT, scaling relations, and microkinetic modeling allows for a rational selection of novel catalysts that can deliver efficient glycerol electrooxidation, low cost of production, and environmental sustainability. Activity and chemical selectivity towards hydrogen production on pure metal catalysts is discussed in terms of volcano-shaped plots. We find that the selectivity in the glycerol oxidation reaction is influenced by a different energy landscape when in the presence of water and best classified by a comparison of O—H and C—H bond-breaking barriers. In addition, we screened 3570 bi-metallic catalysts in the AB (L1 0 ) and A 3 B (L1 2 ) ordered structures for activity, stability, price, and toxicity. By filtering based on the criteria for toxicity, resistance to oxidation, miscibility, and price, we have identified 5 L1 0 structured catalysts (AgPd, AuPd, PtSb, CuPt, and AgPt) and 20 L1 2 catalysts (Ga 3 Ta, In 3 Ta, Ir 3 W, Ir 3 Mo, Cu 3 Pt, Ir 3 Ta, Ir 3 Re, Pd 3 Bi, Pd 3 Cu, Pd 3 W, Pd 3 Co, Pd 3 Sn, Pd 3 Mo, Pd 3 Ag, Pd 3 Ga, Pd 3 Ta, Au 3 Ru, Pd 3 In, Au 3 Ir, and Pd 3 Au) that are all predicted to show high activity. We also identify an additional 37 L1 0 and 92 L1 2 structured electrocatalysts with an anticipated medium-high activity.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Sampling lattices in semi-grand canonical ensemble with autoregressive machine learning
Calculating thermodynamic potentials and observables efficiently and accurately is key for the application of statistical mechanics simulations to materials science. However, naive Monte Carlo approaches, on which such calculations are often dependent, struggle to scale to complex materials in many state-of-the-art disciplines such as the design of high entropy alloys or multi-component catalysts. To address this issue, we adapt sampling tools built upon machine learning-based generative modeling to the materials space by transforming them into the semi-grand canonical ensemble. Furthermore, we show that the resulting models are transferable across wide ranges of thermodynamic conditions and can be implemented with any internal energy model U, allowing integration into many existing materials workflows. We demonstrate the applicability of this approach to the simulation of benchmark systems (AgPd, CuAu) that exhibit diverse thermodynamic behavior in their phase diagrams. Finally, we discuss remaining challenges in model development and promising research directions for future improvements.
36 MATERIALS SCIENCE↗
Multi-electrode/multi-modal atmospheric pressure glow discharge plasma ionization device
Apparatus include an atmospheric pressure glow discharge (APGD) analyte electrode defining an analyte discharge axis into an APGD volume, and a plurality of APGD counter electrodes having respective electrical discharge ends directed to the APGD volume, wherein the APGD analyte electrode and the APGD counter electrodes are configured to produce an APGD plasma in the APGD volume with a voltage difference between the APGD analyte electrode and one or more of the AGPD counter electrodes. An electrode can be integrated into an ion inlet. Apparatus can be configured to perform auto-ignition and/or provide multi-modal operation through selectively powering electrodes. Electrode holder devices are disclosed. Related methods are disclosed.
Koppenaal, David W.↗