SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Here we provide direct evidence for the formation of an Fe V (O)(OH) species in non-haem iron catalysis using ambient mass spectrometry.
An important activity/selectivity trade-off occurs at increased olefin oligomerization temperatures. Jet-range product decreases and paraffin formation increases at high oligomerization temperatures.
A major challenge for the design of noble metal nanocatalysts is the ability of surface engineering to enhance the activity and stability with minimum use of the noble metals.
The stability of zeolite Sn-beta (Sn-β) was greatly improved for glucose isomerization to fructose and fructose yield of 41.5% has been obtained when dioxane/water was used as solvent. The effect of dioxane/water solvent mixtures for fructose dehydration on Amberlyst-131 was also studied and it was found that small amounts of water in dioxane increase the yield of HMF (up to 74%) by limiting the formation of oligomers like difructose anhydride (III). 56% yield of HMF from glucose, maltose, trehalose or cellobiose and 60% from sucrose were produced when hydrolysis of disaccharides, glucose isomerization and fructose dehydration were coupled in a mixture of dioxane/water (5 wt%).
The facet-dependent strain effects on the hydrogen evolution reaction catalyzed by CoP were studied using density functional theory methods. We show that both atomic and electronic effects need to be taken into consideration to understand the strain effects. For the (111) surface, tensile strain promotes hydrogen evolution at all the levels of hydrogen coverage. For the (101) surface, a moderate tensile strain of ~3% endows this facet with optimum performance.
Herein is reported the electrocatalytic reduction of CO 2 with the complex [Ni(bis-NHC)(dmpe)] 2+ ( 1 ) (bis-NHC = 1,l′:3,3′-bis(1,3-propanediyl)dibenzimidazolin-2,2′-diylidene; dmpe = 1,2-bis(dimethylphosphino)ethane).
We explored the production of levoglucosenone from levoglucosan using propylsulfonic acid functionalized silica; 59% selectivity was obtained at 100% conversion.
This work explores the concept of structurally tailored and engineered macromolecular (STEM) networks by proposing a novel metal-free approach to prepare the networks.
Metallic Pd and/or reduced Pd oxide on Pd–TiO 2 is found to be the intrinsic active site for O 2 removal.
Isolated Fe sites achieve enhanced intrinsic activity for nitrate electroreduction to ammonia with ∼100% selectivity, which effectively inhibit water dissociation through a nitrate-preoccupation mechanism.
Zirconia supported tungstates catalyze octadecanol dehydration, an important step in the carbon preserving conversion of triglycerides to fuels.
New photocatalysts can be prepared via heterogenization of molecular complexes and creation of atomically dispersed sites on surfaces. Structural investigation of such surface catalytic sites requires extensive use of spectroscopic techniques.
Tandem catalysis couples multiple reactions and promises to improve chemical processing, but precise spatiotemporal control over reactive intermediates remains elusive. We used atomic layer deposition to grow In 2 O 3 over Pt/Al 2 O 3 , and this nanostructure kinetically couples the domains through surface hydrogen atom transfer, resulting in propane dehydrogenation (PDH) to propylene by platinum, then selective hydrogen combustion by In 2 O 3 , without excessive hydrocarbon combustion. Other nanostructures, including platinum on In 2 O 3 or platinum mixed with In 2 O 3 , favor propane combustion because they cannot organize the reactions sequentially. The net effect is rapid and stable oxidative dehydrogenation of propane at high per-pass yields exceeding the PDH equilibrium. Tandem catalysis using this nanoscale overcoating geometry is validated as an opportunity for highly selective catalytic performance in a grand challenge reaction.
Explore the source record for details and available documents.
The challenge of elucidating the chemical mechanisms by which nano- and other particles form, and then using those mechanisms to understand, analyze, and ideally predict particle-size and particle-size distributions, was undertaken. Thanks to multi-year, longer-term DOE support each of these challenges was successfully met. The community is now able to both predict, and control in cases where the underlying mechanism of particle formation has been determined, the key PS and PSD that are, in turn, critical properties that strongly influence the catalytic and other physical properties of nano- and larger particles across nature.
The data underlying this published work have been made publicly available in this repository as part of the IMASC Data Management Plan. This work was supported as part of the Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0012573.