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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on U2(PdRh)3 by Materials Project

U2(RhPd)3 is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. U is bonded to six Rh and six Pd atoms to form UPd6Rh6 cuboctahedra that share corners with twelve equivalent UPd6Rh6 cuboctahedra, edges with twelve RhU4Pd6Rh2 cuboctahedra, edges with twelve PdU4Pd4Rh4 cuboctahedra, faces with six equivalent UPd6Rh6 cuboctahedra, faces with six RhU4Pd6Rh2 cuboctahedra, and faces with six PdU4Pd4Rh4 cuboctahedra. All U–Rh bond lengths are 2.84 Å. There are a spread of U–Pd bond distances ranging from 2.88–2.97 Å. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded to four equivalent U, two equivalent Rh, and six Pd atoms to form distorted RhU4Pd6Rh2 cuboctahedra that share corners with twelve equivalent RhU4Pd6Rh2 cuboctahedra, edges with four equivalent RhU4Pd4Rh4 cuboctahedra, edges with eight equivalent UPd6Rh6 cuboctahedra, edges with twelve PdU4Pd4Rh4 cuboctahedra, faces with four equivalent UPd6Rh6 cuboctahedra, faces with six PdU4Pd4Rh4 cuboctahedra, and faces with eight RhU4Pd6Rh2 cuboctahedra. Both Rh–Rh bond lengths are 2.92 Å. There are four shorter (2.88 Å) and two longer (2.92 Å) Rh–Pd bond lengths. In the second Rh site, Rh is bonded to four equivalent U, four equivalent Rh, and four equivalent Pd atoms to form distorted RhU4Pd4Rh4 cuboctahedra that share corners with four equivalent RhU4Pd4Rh4 cuboctahedra, corners with eight equivalent PdU4Pd4Rh4 cuboctahedra, edges with eight equivalent UPd6Rh6 cuboctahedra, edges with eight equivalent RhU4Pd6Rh2 cuboctahedra, edges with eight equivalent PdU4Pd4Rh4 cuboctahedra, faces with four equivalent UPd6Rh6 cuboctahedra, faces with six PdU4Pd4Rh4 cuboctahedra, and faces with eight RhU4Pd6Rh2 cuboctahedra. All Rh–Pd bond lengths are 2.84 Å. There are three inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent U, four equivalent Rh, and four equivalent Pd atoms to form distorted PdU4Pd4Rh4 cuboctahedra that share corners with four equivalent PdU4Pd4Rh4 cuboctahedra, corners with eight equivalent RhU4Pd4Rh4 cuboctahedra, edges with eight equivalent UPd6Rh6 cuboctahedra, edges with eight equivalent RhU4Pd6Rh2 cuboctahedra, edges with eight equivalent PdU4Rh8 cuboctahedra, faces with four equivalent UPd6Rh6 cuboctahedra, faces with six RhU4Pd6Rh2 cuboctahedra, and faces with eight PdU4Pd4Rh4 cuboctahedra. All Pd–Pd bond lengths are 2.84 Å. In the second Pd site, Pd is bonded to four equivalent U and eight Rh atoms to form PdU4Rh8 cuboctahedra that share corners with twelve PdU4Rh8 cuboctahedra, edges with eight equivalent UPd6Rh6 cuboctahedra, edges with eight equivalent RhU4Pd6Rh2 cuboctahedra, edges with eight equivalent PdU4Pd4Rh4 cuboctahedra, faces with four equivalent UPd6Rh6 cuboctahedra, faces with six PdU4Rh8 cuboctahedra, and faces with eight RhU4Pd6Rh2 cuboctahedra. In the third Pd site, Pd is bonded to four equivalent U, four equivalent Rh, and four equivalent Pd atoms to form PdU4Pd4Rh4 cuboctahedra that share corners with twelve PdU4Rh8 cuboctahedra, edges with eight equivalent UPd6Rh6 cuboctahedra, edges with sixteen RhU4Pd6Rh2 cuboctahedra, faces with four equivalent UPd6Rh6 cuboctahedra, faces with four equivalent RhU4Pd6Rh2 cuboctahedra, and faces with ten PdU4Pd4Rh4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PdRh(NO)10 by Materials Project

RhNPdN4(NO2)5 crystallizes in the monoclinic P2_1/m space group. The structure is zero-dimensional and consists of two azanide;palladium molecules, ten nitrous acid molecules, and two RhN clusters. In each RhN cluster, Rh4+ is bonded in a single-bond geometry to one N+1.40+ atom. The Rh–N bond length is 1.66 Å. N+1.40+ is bonded in a single-bond geometry to one Rh4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ce2(PdRh)3 by Materials Project

Ce2(RhPd)3 is Uranium Silicide-derived structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Ce is bonded to six Rh and six Pd atoms to form CePd6Rh6 cuboctahedra that share corners with twelve equivalent CePd6Rh6 cuboctahedra, edges with eight RhCe4Pd4Rh4 cuboctahedra, edges with twelve PdCe4Pd2Rh6 cuboctahedra, faces with four RhCe4Pd4Rh4 cuboctahedra, faces with six equivalent CePd6Rh6 cuboctahedra, and faces with six PdCe4Pd2Rh6 cuboctahedra. There are a spread of Ce–Rh bond distances ranging from 2.86–2.92 Å. All Ce–Pd bond lengths are 2.95 Å. There are three inequivalent Rh sites. In the first Rh site, Rh is bonded to four equivalent Ce, four equivalent Rh, and four equivalent Pd atoms to form distorted RhCe4Pd4Rh4 cuboctahedra that share corners with four equivalent RhCe4Pd4Rh4 cuboctahedra, corners with eight equivalent PdCe4Pd4Rh4 cuboctahedra, edges with eight equivalent CePd6Rh6 cuboctahedra, edges with eight equivalent RhCe4Pd8 cuboctahedra, edges with eight equivalent PdCe4Pd2Rh6 cuboctahedra, faces with four equivalent CePd6Rh6 cuboctahedra, faces with four equivalent RhCe4Pd4Rh4 cuboctahedra, and faces with six PdCe4Pd2Rh6 cuboctahedra. All Rh–Rh bond lengths are 2.94 Å. All Rh–Pd bond lengths are 2.89 Å. In the second Rh site, Rh is bonded to four equivalent Ce and eight Pd atoms to form RhCe4Pd8 cuboctahedra that share corners with four equivalent RhCe4Pd8 cuboctahedra, edges with eight equivalent CePd6Rh6 cuboctahedra, edges with eight equivalent RhCe4Pd4Rh4 cuboctahedra, edges with eight equivalent PdCe4Pd2Rh6 cuboctahedra, faces with four equivalent CePd6Rh6 cuboctahedra, faces with four equivalent RhCe4Pd8 cuboctahedra, and faces with eight PdCe4Pd2Rh6 cuboctahedra. There are four shorter (2.92 Å) and four longer (2.94 Å) Rh–Pd bond lengths. In the third Rh site, Rh is bonded in a distorted square co-planar geometry to four equivalent Ce, four equivalent Rh, and four equivalent Pd atoms. All Rh–Pd bond lengths are 2.92 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent Ce, six Rh, and two equivalent Pd atoms to form distorted PdCe4Pd2Rh6 cuboctahedra that share corners with twelve equivalent PdCe4Pd2Rh6 cuboctahedra, edges with four equivalent PdCe4Pd4Rh4 cuboctahedra, edges with eight equivalent CePd6Rh6 cuboctahedra, edges with eight RhCe4Pd4Rh4 cuboctahedra, faces with four equivalent CePd6Rh6 cuboctahedra, faces with four RhCe4Pd4Rh4 cuboctahedra, and faces with eight PdCe4Pd2Rh6 cuboctahedra. Both Pd–Pd bond lengths are 2.89 Å. In the second Pd site, Pd is bonded to four equivalent Ce, four equivalent Rh, and four equivalent Pd atoms to form distorted PdCe4Pd4Rh4 cuboctahedra that share corners with four equivalent PdCe4Pd4Rh4 cuboctahedra, corners with eight equivalent RhCe4Pd4Rh4 cuboctahedra, edges with eight equivalent CePd6Rh6 cuboctahedra, edges with eight equivalent PdCe4Pd2Rh6 cuboctahedra, faces with four equivalent CePd6Rh6 cuboctahedra, faces with six RhCe4Pd4Rh4 cuboctahedra, and faces with eight PdCe4Pd2Rh6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2(PdRh)3 by Materials Project

Zr2(RhPd)3 is Uranium Silicide-derived structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Zr is bonded to six Rh and six Pd atoms to form ZrPd6Rh6 cuboctahedra that share corners with twelve equivalent ZrPd6Rh6 cuboctahedra, edges with twelve RhZr4Pd4Rh4 cuboctahedra, edges with twelve PdZr4Pd2Rh6 cuboctahedra, faces with six equivalent ZrPd6Rh6 cuboctahedra, faces with six RhZr4Pd4Rh4 cuboctahedra, and faces with six PdZr4Pd2Rh6 cuboctahedra. There are a spread of Zr–Rh bond distances ranging from 2.80–2.84 Å. All Zr–Pd bond lengths are 2.85 Å. There are three inequivalent Rh sites. In the first Rh site, Rh is bonded to four equivalent Zr, four equivalent Rh, and four equivalent Pd atoms to form distorted RhZr4Pd4Rh4 cuboctahedra that share corners with four equivalent RhZr4Pd4Rh4 cuboctahedra, corners with eight equivalent PdZr4Pd4Rh4 cuboctahedra, edges with eight equivalent ZrPd6Rh6 cuboctahedra, edges with eight equivalent RhZr4Pd8 cuboctahedra, edges with eight equivalent PdZr4Pd2Rh6 cuboctahedra, faces with four equivalent ZrPd6Rh6 cuboctahedra, faces with six PdZr4Pd2Rh6 cuboctahedra, and faces with eight RhZr4Pd4Rh4 cuboctahedra. All Rh–Rh bond lengths are 2.85 Å. All Rh–Pd bond lengths are 2.82 Å. In the second Rh site, Rh is bonded to four equivalent Zr and eight Pd atoms to form RhZr4Pd8 cuboctahedra that share corners with twelve RhZr4Pd8 cuboctahedra, edges with eight equivalent ZrPd6Rh6 cuboctahedra, edges with eight equivalent RhZr4Pd4Rh4 cuboctahedra, edges with eight equivalent PdZr4Pd2Rh6 cuboctahedra, faces with four equivalent ZrPd6Rh6 cuboctahedra, faces with six RhZr4Pd8 cuboctahedra, and faces with eight PdZr4Pd2Rh6 cuboctahedra. There are four shorter (2.84 Å) and four longer (2.85 Å) Rh–Pd bond lengths. In the third Rh site, Rh is bonded to four equivalent Zr, four equivalent Rh, and four equivalent Pd atoms to form distorted RhZr4Pd4Rh4 cuboctahedra that share corners with twelve RhZr4Pd8 cuboctahedra, edges with eight equivalent ZrPd6Rh6 cuboctahedra, edges with sixteen PdZr4Pd2Rh6 cuboctahedra, faces with four equivalent ZrPd6Rh6 cuboctahedra, faces with four equivalent PdZr4Pd2Rh6 cuboctahedra, and faces with ten RhZr4Pd4Rh4 cuboctahedra. All Rh–Pd bond lengths are 2.83 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent Zr, six Rh, and two equivalent Pd atoms to form distorted PdZr4Pd2Rh6 cuboctahedra that share corners with twelve equivalent PdZr4Pd2Rh6 cuboctahedra, edges with four equivalent PdZr4Pd4Rh4 cuboctahedra, edges with eight equivalent ZrPd6Rh6 cuboctahedra, edges with twelve RhZr4Pd4Rh4 cuboctahedra, faces with four equivalent ZrPd6Rh6 cuboctahedra, faces with six RhZr4Pd4Rh4 cuboctahedra, and faces with eight PdZr4Pd2Rh6 cuboctahedra. Both Pd–Pd bond lengths are 2.82 Å. In the second Pd site, Pd is bonded to four equivalent Zr, four equivalent Rh, and four equivalent Pd atoms to form distorted PdZr4Pd4Rh4 cuboctahedra that share corners with four equivalent PdZr4Pd4Rh4 cuboctahedra, corners with eight equivalent RhZr4Pd4Rh4 cuboctahedra, edges with eight equivalent ZrPd6Rh6 cuboctahedra, edges with eight equivalent RhZr4Pd4Rh4 cuboctahedra, edges with eight equivalent PdZr4Pd2Rh6 cuboctahedra, faces with four equivalent ZrPd6Rh6 cuboctahedra, faces with six RhZr4Pd4Rh4 cuboctahedra, and faces with eight PdZr4Pd2Rh6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PdRh by Materials Project

RhPd is alpha La-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Rh sites. In the first Rh site, Rh is bonded to six equivalent Rh and six Pd atoms to form RhPd6Rh6 cuboctahedra that share corners with twelve RhPd6Rh6 cuboctahedra, edges with twelve RhPd6Rh6 cuboctahedra, edges with twelve PdPd6Rh6 cuboctahedra, faces with six equivalent RhPd6Rh6 cuboctahedra, and faces with twelve PdPd6Rh6 cuboctahedra. All Rh–Rh bond lengths are 2.76 Å. All Rh–Pd bond lengths are 2.75 Å. In the second Rh site, Rh is bonded to ten equivalent Rh and six Pd atoms to form RhPd6Rh10 cuboctahedra that share corners with ten PdPd6Rh6 cuboctahedra, corners with twelve RhPd6Rh6 cuboctahedra, edges with eight PdPd6Rh6 cuboctahedra, edges with sixteen RhPd6Rh6 cuboctahedra, faces with sixteen equivalent RhPd6Rh10 cuboctahedra, and faces with eighteen PdPd6Rh6 cuboctahedra. There are a spread of Rh–Rh bond distances ranging from 2.76–5.52 Å. All Rh–Pd bond lengths are 2.75 Å. There are three inequivalent Pd sites. In the first Pd site, Pd is bonded to six equivalent Rh and six equivalent Pd atoms to form PdPd6Rh6 cuboctahedra that share corners with twelve PdPd6Rh6 cuboctahedra, edges with twelve equivalent RhPd6Rh6 cuboctahedra, edges with twelve PdPd6Rh6 cuboctahedra, faces with six equivalent PdPd6Rh6 cuboctahedra, and faces with twelve equivalent RhPd6Rh6 cuboctahedra. All Pd–Pd bond lengths are 2.76 Å. In the second Pd site, Pd is bonded to six Rh and six equivalent Pd atoms to form PdPd6Rh6 cuboctahedra that share corners with five equivalent RhPd6Rh10 cuboctahedra, corners with twelve PdPd6Rh6 cuboctahedra, edges with ten RhPd6Rh6 cuboctahedra, edges with twelve PdPd6Rh6 cuboctahedra, faces with six equivalent PdPd6Rh6 cuboctahedra, and faces with fifteen RhPd6Rh6 cuboctahedra. All Pd–Rh bond lengths are 2.75 Å. All Pd–Pd bond lengths are 2.76 Å. In the third Pd site, Pd is bonded to six Rh and six equivalent Pd atoms to form PdPd6Rh6 cuboctahedra that share corners with five equivalent RhPd6Rh10 cuboctahedra, corners with twelve PdPd6Rh6 cuboctahedra, edges with ten RhPd6Rh6 cuboctahedra, edges with twelve PdPd6Rh6 cuboctahedra, faces with six equivalent PdPd6Rh6 cuboctahedra, and faces with fifteen RhPd6Rh6 cuboctahedra. All Pd–Pd bond lengths are 2.76 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Synthesis of amorphous Pd-based nanocatalysts for efficient alcoholysis of styrene oxide and electrochemical hydrogen evolution

Amorphous nanomaterials with long-range disordered structures could possess distinct properties and promising applications, especially in catalysis, as compared with their conventional crystalline counterparts. It is imperative to achieve the controlled preparation of amorphous noble metal-based nanomaterials for the exploration of their phase-dependent applications. Here, in this work, we report a facile wet-chemical reduction strategy to synthesize various amorphous multimetallic Pd-based nanomaterials, including PdRu, PdRh, and PdRuRh. The phase-dependent catalytic performances of distinct Pd-based nanomaterials towards diverse catalytic applications have been demonstrated. Specifically, the usage of PdRu nanocatalysts with amorphous and crystalline face-centered cubic (fcc) phases can efficiently switch the ring-opening route of styrene oxide to obtain different products with high selectivity through alcoholysis reaction and hydrogenation reaction, respectively. Moreover, when used as an electrocatalyst for hydrogen evolution reaction (HER), the synthesized amorphous PdRh nanocatalyst exhibits low overpotential and high turnover frequency values, outperforming its crystalline fcc counterpart and most of the reported Pd-based HER electrocatalysts.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Mixed Oxygenate Conversion to Sustainable Aviation Fuel via Ketones Intermediate

This report describes our effort in developing Pd based bimetallic catalysts during Tandem ketone condensation-hydrogenation reaction. We have synthesized a series of bimetallic catalysts containing equimolar amount of Pd with various other 3d, 4d and 5d transition and coinage metals. The activity of theses bimetallic catalysts towards C=C and C=O hydrogenation was evaluated using mesityl oxide and 2-heptanone as model compounds. All these catalysts show much higher activity towards C=C hydrogenation compared to C=O hydrogenation at a given temperature and at different H2 pressure, indicated the higher intrinsic activity of Pd based bimetallic catalysts towards C=C hydrogenation. Alloy catalysts with Pd and other 4d and 5d metals such as PdRu, PdRh, PdPt and PdIr shows higher activity towards both C=C and C=O hydrogenation compared to baseline Pd catalyst as well as alloy catalysts containing Pd and 3d transition metals. Among the different Pd-3d metal alloy catalysts, the activity of the bimetallic catalysts depends on alloying transition metals. Although, PdRu, PdRh, PdPt and PdIr catalysts shows very high activity towards C=O hydrogenation of 2-heptanone, the same catalysts didn’t show any C=O hydrogenation when ?,?-unsaturated carbonyl compound such as mesityl oxide was used as the model substrate. Based on these results, it is evident that Pd based bimetallic catalysts are very selective to the C=C hydrogenation and their activity could be tuned by the judicious choice of the alloying elements. Although alloying with Ru, Rh and Pt shows significant rate enhancement in case of C=C hydrogenation reaction, higher cost of those metals prevents their usage in industry as it significantly increases the cost of the catalyst. Considering all the factors, we have identified PdZn as one of promising alternative of Pd catalyst as it shows comparable activity towards C=C hydrogenation and reduces the activity for C=O hydrogenation. Based on the electrochemical CO stripping, we unambiguously established the weaker bonding CO on the PdZn surface compared to pristine Pd and highlight the benefits of its usage due to higher CO tolerance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Impact of Oxygen Storage Components in Prototype Pd-Based Three-Way Catalysts under Exhaust Conditions Relevant to Propane Engines

With increasing concerns about global warming, the push for sustainable and eco-friendly fuels is accelerating. Propane, recognized as liquefied petroleum gas or LPG, has garnered research interest as an alternative fuel due to its notable advantages, including a high-octane rating, reduced greenhouse gas emissions, and potential cost-effectiveness. However, to realize its full potential as an alternative fuel it is essential to develop catalysts that efficiently handle emissions at low temperatures. In our research, we investigated three distinct palladium (Pd)-based three-way catalyst (TWC) formulations (PdRh, Pd-only, and Pd-OSC) to investigate the influence of typical TWC components rhodium (Rh) and oxygen storage components (OSC) in exhaust scenarios relevant to propane-fueled engines. Among these, the formulation containing oxygen storage components (Pd-OSC) showed the highest reactivity for both NO and C 3 H 8 while minimizing performance degradation from hydrothermal aging (HTA). Notably, the temperature of 50% conversion (T50) for propane in the Pd-OSC fresh and HTA sample was lower by 30 °C and 13 °C, respectively, compared to the Pd-only sample, highlighting the role of oxygen storage materials in enhancing catalyst performance, even without dithering. Additionally, N 2 physisorption showed that the PdOSC sample has a higher surface area and increased pore volume. This underscores the idea that OSC materials not only augment the catalyst’s porosity but also optimize reactant accessibility to active sites, thus elevating catalytic efficiency. In addition to evaluating performance, we further explored the performance and characteristics of the catalysts using catalytic probe reactions, such as water–gas shift and steam reforming reactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗