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Results for “FORMIC ACID”

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.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Graphene decorated with PtAu alloy nanoparticles: facile synthesis and promising application for formic acid oxidation

PtAu alloy nanoparticles (~ 3.2 nm in diameter) are synthesized in poly(diallyldimethylammonium chloride) (PDDA) aqueous solution and uniformly dispersed on graphene nanosheets. PtAu/graphene exhibits high electrocatalytic activity and stability for formic acid oxidation, which is attributed to the high dispersion of PtAu nanoparticles and the specific interaction between PtAu and graphene, indicating a promising catalyst for direct formic acid fuel cells. The facile method can be readily extended to the synthesis of other alloy nanoparticles.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2023

High-resolution rovibrational spectroscopy of trans -formic acid in the v 1 OH stretching fundamental: Dark state coupling and evidence for charge delocalization dynamics

High-resolution infrared (IR) reduced-Doppler absorption spectra of jet-cooled gas phase trans-formic acid in the v 1 OH stretching fundamental region are reported for the first time, obtained by supersonically expanding trans- formic acid/Ar mixtures through a slit jet nozzle source and rotationally cooling to T rot ≈ 10.9(5) K, with ab- sorption signals recorded by high-resolution difference-frequency IR absorption spectroscopy. Two a/b-type rovibrational bands of comparable intensity, one ~10-fold weaker b-type band, and one ~6-fold weaker a-type band are observed, with vibrational band origins at 3570.493(5), 3566.793(5), 3560.032(9), and 3534.6869(2) cm –1 , respectively. Based on previous Raman jet spectroscopic work by Nejad and Sibert [A. Nejad, E.L. Sibert III, The Raman jet spectrum of trans-formic acid and its deuterated isotopologs: Combining theory and experi- ment to extend the vibrational database, J. Chem. Phys. 154(6) (2021) 064301.], these four rovibrational bands have been assigned to v 1 , (v 2 + v 7 ), (v 6 + 2v 7 + 2v 9 ), and 2v 3 , respectively. Specifically, two of the three upper dark states (2 1 7 1 (a') and 6 1 7 2 9 2 (a')) are close enough to the “bright” 1 1 (a') state to facilitate strong anharmonic resonance interactions, which results in intensity mixing into the two zero-order bands that would otherwise be “dark”. Furthermore, our high-resolution spectral analysis reveals that there are local rotational crossings be- tween these zero-order 1 1 and 2 1 7 1 states resulting in extra lines (i.e., some upper levels in the nominally v 1 band have majority zero-order 2 1 7 1 state character). This motivates development of a 3 coupled state (1 1 , 2 1 7 1 , and 6 1 7 2 9 2 ) picture to aid in the spectral analysis, which is able to match all 3 observed band origins and relative band intensities, as well as indicate the necessity of multistate (> 2) coupling. Though limited by range of J and Ka levels (J’ ≤ 9 and K a ’ ≤ 3) populated at supersonic jet temperatures, this work offers first precision spec- troscopic analysis of trans-formic acid in the v 1 OH stretch region, which should aid in assignment of the more complete yet highly congested room temperature FTIR spectra. Lastly, and in sharp contrast to the spectral complexity in the three predominantly b-type bands, the lone a-type 2v 3 rovibrational band at 3534.6869(2) cm –1 is well described by a simple, rigid asymmetric top Hamiltonian.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Integrated Technology for Cost-Effective CO2 Capture and Formic Acid Production: Modeling, Optimization, and Economic Analysis

A novel reactive technology is being investigated that electrochemically converts CO2 into valuable chemicals, particularly formic acid. This work focuses on identifying the optimal design and operation of an integrated membrane-based CO2 capture unit with the electrochemical conversion process. In this setup, the CO2 in the flue gas permeates through a CO2-selective membrane and enters an electrolyzer to produce formic acid, creating an integrated reaction module. To refine the chemical product, gas products from the electrolyzer are directed to a pressure swing adsorption unit, while the liquid product undergoes refinement to achieve commercial-grade formic acid using reactive distillation. A membrane CO2 capture model and an electrochemical conversion model have been developed using the IDAES Integrated Platform (Institute for the Design of Advanced Energy System), facilitating rigorous flowsheet modeling and process design and optimization.

Wang, Maojian↗
DOE OSTI2011

GLYCOLIC-FORMIC ACID FLOWSHEET SLUDGE MATRIX STUDY

Testing was completed to demonstrate the viability of the newly developed glycolic acid/formic acid flowsheet on processing in the Defense Waste Processing Facility's (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in DWPF. Four sludge simulants were prepared to cover two compositional ranges in the waste. The first was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium (referred to as HiMn or LoMn in this report). These two options can be combined to form four distinct sludge compositions. The sludge matrix study called for testing each of these four simulants near the minimum acid required for nitrite destruction (100% acid stoichiometry) and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid (150% acid stoichiometry). Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants were used for high and low acid testing. Eight planned experiments (GF26 to GF33) were completed to demonstrate the viability of the glycolic-formic flowsheet. Composition and physical property measurements were made on the SRAT product. Composition measurements were made on the condensate from the Mercury Water Wash Tank (MWWT), Formic Acid Vent Condenser (FAVC), ammonia scrubber and on SRAT samples pulled throughout the SRAT cycle. Updated values for formate loss and nitrite-tonitrate conversion were found that can be used in the acid calculations for future sludge matrix process simulations with the glycolic acid/formic acid flowsheet. Preliminary results of the initial testing indicate: (1) Hydrogen generation rate was very low throughout all SRAT cycles. (2) The mercury concentration of the SRAT product was below the 0.8 wt% limit in all runs. (3) Nitrite in the SRAT product was <100 mg/kg for all runs. (4) Foaminess was not an issue using the nominal antifoam addition strategy in these tests. (5) The high aluminum sludges (LoFe, HM type sludges) were much more viscous than the Hi Fe sludges. At 100% acid stoichiometry, the SRAT products from the high aluminum sludges were very viscous but at 150% acid stoichiometry, the SRAT products from the high aluminum sludges were very thin. This makes the glycolic acid/formic acid flowsheet an improvement for processing more viscous sludges. (6) The pH of the SRAT products was from 2.7-3.1 for the 150% acid stoichiometry runs and 5.1-6.1 for the 100% acid stoichiometry runs, significantly lower than is typical of the baseline nitric acid/formic acid flowsheet.

08 HYDROGEN↗
DOE OSTI2018

Method and system for electrochemical production of formic acid from carbon dioxide

An electrochemical device converts carbon dioxide to a formic acid reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each have reactant introduced thereto. Two membranes, a cation exchange polymer electrolyte membrane and an anion exchange polymer electrolyte membrane, are interposed between the anode and the cathode, forming a central flow compartment where a carbon dioxide reduction product, such as formic acid, can be recovered. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm 2 , measured as the area of the cathode gas diffusion layer that is covered by catalyst, and formate ion selectivity is at least 50% at a cell potential difference of 3.0 V. In some embodiments, at least one polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

Source record↗
DOE OSTI2022

Formation and detection of metastable formic acid in a supersonic expansion: High resolution infrared spectroscopy of the jet-cooled cis -HCOOH conformer

High-resolution direct absorption infrared spectra of metastable cis-formic acid (HCOOH) trapped in a cis-well resonance behind a 15 kcal/mol barrier are reported for the first time, with the energetically unstable conformer produced in a supersonic slit plasma expansion of trans-formic acid/H 2 mixtures. We present a detailed high-resolution rovibrational analysis for cis-formic acid species in the OH stretch (ν 1 ) fundamental, providing first precision vibrational band origin, rotational constants, and term values, which in conjunction with ab initio calculations at the couple-cluster with single, double, and perturbative triple [CCSD(T)]/ANOn (n = 0, 1, 2) level support the experimental assignments and establish critical points on the potential energy surface for internal rotor trans-to-cis isomerization. Relative intensities for a- and b-type transitions observed in the spectra permit the transition dipole moment components to be determined in the body fixed frame and prove to be in good agreement with ab initio CCSD(T) theoretical estimates but in poor agreement with simple bond-dipole predictions. As a result, the observed signal dependence on H 2 in the discharge suggests the presence of a novel H atom radical chemical mechanism for strongly endothermic “up-hill” internal rotor isomerization between trans- and cis-formic acid conformers.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Carbon Dioxide Hydrogenation and Formic Acid Dehydrogenation Catalyzed by Iridium Complexes Bearing Pyridyl-pyrazole Ligands: Effect of an Electron-donating Substituent on the Pyrazole Ring on the Catalytic Activity and Durability

Cp*Ir (Cp*=pentamethylcyclopentadienyl) complexes with an N,N–bidentate ligand such as 2,2'–bipyridine serve as catalysts for both carbon dioxide (CO 2 ) hydrogenation to formate and formic acid dehydrogenation in water. Previously, it was shown that the introduction of an electron–donating substituent on 2,2'–bipyridine is an effective method to improve the catalytic activity. Especially, the highly electron–donating hydroxyl (OH) substituent performs much better than other substituents such as methyl or methoxy under basic conditions. However, the introduction of an OH substituent on the ligand has been limited to six–membered rings such as pyridine or pyrimidine. These results prompted us to develop a new ligand comprising a pyridyl–pyrazole with an OH group on the pyrazole moiety for Cp*Ir–catalyzed CO 2 hydrogenation and formic acid dehydrogenation. In conclusion, the resultant catalyst showed high catalytic activity in CO 2 hydrogenation and excellent robustness in formic acid dehydrogenation with a turnover number of 10 million.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Enabling Stable and Salt-Free Formic Acid Production via Reactive Interface Optimization in Forward-Bias Bipolar-Membrane CO2 Electrolyzers

Electrochemical conversion of CO2 to liquid products is limited by parasitic reactions that consume products and destabilize operation. Here, we show that salt-free formic acid synthesis in a forward-bias bipolar-membrane CO2 electrolyzer is governed by a coupled reaction-transport instability driven by parasitic anode formic acid oxidation. Operando mass spectrometry reveals that this process proceeds through CO-mediated poisoning, identifying catalyst tolerance to CO as a key descriptor of anode selectivity. Among the catalysts examined, PtRu/C preferentially promotes hydrogen oxidation over formic acid oxidation. Coupling this catalyst with transport-interface engineering improves product removal, enhances Faradaic and energy efficiency, and enables stable operation at 200 mA/cm2 for 190 h with a voltage decay of 0.64 mV/h. Techno-economic analysis indicates an 18% reduction in minimum selling price and highlights product concentration as the dominant cost lever. These results establish a general framework for suppressing product oxidation in liquid-product electrolyzers.

Hu, Leiming↗
DOE OSTI2011

CO 2 Hydrogenation to Formic Acid on Ni(111)

Periodic, self-consistent, density functional theory (DFT) calculations are employed to study CO 2 hydrogenation on Ni(111). CO 2 hydrogenation with H adsorbed on the surface and with H absorbed in the subsurface is investigated systematically, and the respective microscopic reaction mechanisms are elucidated. We show that on Ni(111) CO 2 hydrogenation to formate intermediate is more favorable than to carboxyl intermediate. The hydrogenation to formate goes through the unidentate structure that rapidly transforms into the bidentate structure. Further hydrogenation from formate to formic acid is energetically more difficult than formate formation. Formation of adsorbed formic acid from adsorbed CO 2 and surface hydrogen is an endothermic reaction. Because subsurface H in Ni(111) is substantially less stable compared to surface H, its reaction with adsorbed CO 2 to adsorbed formic acid is an exothermic one. Finally, our results may have significant implications for the synthesis of liquid fuels from CO 2 and for catalytic hydrogenation reactions in general.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2024

Life Cycle Assessment of Formic Acid as a Liquid Hydrogen Carrier

This work presents a life cycle analysis of the transport and processing for formic acid into hydrogen. The system boundary begins at the formic acid plant gate and ends with hydrogen end use. The functional unit is 1 kg of hydrogen delivered to end use, 1 kWh for electricity generation, and 1 vehicle mile traveled (VMT). Renewable electricity reduced GWP by 80-90% relative to U.S. average grid.

Shen, Xinyao [NETL Site Support Contractor, Nation↗
DOE OSTI2012

CO2 Hydrogenation to Formic Acid on Ni(110)

Hydrogen (H) in the subsurface of transition-metal surfaces exhibits unique reactivity for heterogeneously catalyzed hydrogenation reactions. Here, we explore the potential of subsurface H for hydrogenating carbon dioxide (CO2) on Ni(110). The energetics of surface and subsurface H reacting with surface CO2 to form formate, carboxyl, and formic acid on Ni(110) is systematically studied using self-consistent, spin-polarized, periodic density functional theory (DFT-GGA-PW91) calculations. We show that on Ni(110), CO2 can be hydrogenated to formate by surface H. However, further hydrogenation of formate to formic acid by surface H is hindered by a larger activation energy barrier. The relative energetics of hydrogenation barriers is reversed for the carboxyl-mediated route to formic acid.We suggest that the energetics of subsurface H emerging to the surface is suitable for providing the extra energy needed to overcome the barrier to formate hydrogenation. CO2 hydrogenation to formic acid could take place on Ni(110) when subsurface H is available to react with CO2. Additional electronic-structure based dynamic calculations would be needed to elucidate the detailed reaction paths for these transformations.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2022

Upgrading the Performance and Stability of Lithium, Manganese-Rich Layered Oxide Cathodes with Combined-Formic Acid and Spinel Coating Treatment

We report improving sluggish rate performance and cycling stability of Li, Mn-rich cathode materials (LMR) is of great importance for practical implementation. Here, dual surface modification on LMR particles with formic acid washing and spinel coating improves the electrochemical performance. Dilute formic acid can remove the Li2CO3 surface impurities and selectively reduce Ni while significantly increasing specific surface area by ~32 %, unlocking more electrochemically active surfaces. Spinel coating enhances cycle stability by suppressing detrimental side reactions at electrode-electrolyte interfaces at high voltage. Post-annealing temperature was found to significantly affect the cathode performance. Higher temperature favors diffusion of transition metal (TM)/Li ions of the spinel coating from surface to the bulk, removing the coating by possible reconstruction into the layered structure and thus degrading the performance. The spinel coating also appears to increase Co 3+ segregation on the particle surface. Compared to the original material, the optimized sample demonstrates 47 % higher capacity retention at 3C and retains 89 % of initial capacity after 150 cycles at 0.5C. Besides, the specific energy density of 523 Wh kg -1 can be attained after 150 cycles at 0.5C. Moreover, the post-cycling analysis of modified sample verifies a better structural integrity with less particle cracking. Altogether, this study portrays an alternative strategy to overcome the shortcomings of LMR cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2019

Kinetic Isolation between Turnovers on Au 18 Nanoclusters: Formic Acid Decomposition One Molecule at a Time

Formic acid (HCOOH or FA) is a clean, safe, and renewable hydrogen storage material. Although Au catalysts decompose vapor-phase FA with high activity and selectivity toward hydrogen, the active site and reaction mechanism remain unclear. Here, we show that the subnanometric Au 18 cluster (0.8 nm in diameter) is likely the active species for FA decomposition. We performed coverage self-consistent, density functional theory-based kinetic Monte Carlo simulations of FA decomposition on gas-phase Au18 clusters, predicting 100% selectivity toward hydrogen and turnover frequencies close to experimentally determined values. The active site is made up of a triangular ensemble of three atoms each possessing a coordination number of 5. Although there are two active site ensembles on the Au18 cluster, their occupations are strongly correlated because of strong, stabilizing interactions between pairs of open-shell adsorbates mediated by the superatomic nature of the cluster. Because the occupation of the active sites blocks the dissociation of additional HCOOH molecules, there is kinetic isolation between turnovers: only one HCOOH molecule can dissociate on the cluster at a time. This explains the extraordinary, experimentally observed selectivity of Au catalysts toward HD during decomposition of HCOOD and DCOOH. Our work offers nanoscale insights into the reaction mechanisms of FA decomposition over Au. This represents a rare example of heterogeneous catalysis by a cluster that catalyzes reactants one molecule at a time. Our work on Au18 thus sheds light on how the unique electronic properties of subnanometric clusters can be used to design quasi-molecular catalysts with high activity and selectivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Electrodeposited Sn–Cu@Sn dendrites for selective electrochemical CO 2 reduction to formic acid

Large-scale CO 2 electrolysis can be applied to store renewable energy in chemicals. Recent developments in gas diffusion electrodes now enable a commercially relevant current density. However, the low selectivity of the CO 2 reduction reaction (CO 2 RR) still hinders practical applications. The selectivity of the CO 2 RR highly depends on the electrocatalyst. Sn catalysts are considered promising cathode materials for the production of formic acid. The selectivity of Sn catalysts can be regulated by controlling their morphology or alloying them with secondary metals. In this work, we enhanced the selectivity of CO 2 reduction to formic acid by synthesizing Sn–Cu@Sn dendrites that have a core@shell architecture. The Sn–Cu@Sn dendrites were prepared by a scalable electro-deposition method. The electronic structure was modified to suppress a reaction pathway for CO production on the Sn surface. Notably, the Sn shell inhibited the cathodic corrosion of Cu during the CO 2 RR. On a gas diffusion electrode, the Sn–Cu@Sn dendrites exhibited 84.2% faraday efficiency to formic acid for 120 h with high stability.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2016

High Upward Fluxes of Formic Acid from a Boreal Forest Canopy

Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH fluxes were bidirectional but mostly upward during daytime, in contrast to studies elsewhere that reported mostly downward fluxes. Downward flux episodes were explained well by modeled dry deposition rates. The sum of net observed flux and modeled dry deposition yields an upward gross flux of HCOOH, which could not be quantitatively explained by literature estimates of direct vegetative soil emissions nor by efficient chemical production from other volatile organic compounds, suggesting missing or greatly underestimated HCOOH sources in the boreal ecosystem. We implemented a vegetative HCOOH source into the GEOS-Chem chemical transport model to match our derived gross flux and evaluated the updated model against airborne and spaceborne observations. Model biases in the boundary layer were substantially reduced based on this revised treatment, but biases in the free troposphere remain unexplained.

forest↗
DOE OSTI2016

High upward fluxes of formic acid from a boreal forest canopy

Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH fluxes were bidirectional but mostly upward during daytime, in contrast to studies elsewhere that reported mostly downward fluxes. Downward flux episodes were explained well by modeled dry deposition rates. The sum of net observed flux and modeled dry deposition yields an upward “gross flux” of HCOOH, which could not be quantitatively explained by literature estimates of direct vegetative/soil emissions nor by efficient chemical production from other volatile organic compounds, suggesting missing or greatly underestimated HCOOH sources in the boreal ecosystem. Here, we implemented a vegetative HCOOH source into the GEOS-Chem chemical transport model to match our derived gross flux and evaluated the updated model against airborne and spaceborne observations. Model biases in the boundary layer were substantially reduced based on this revised treatment, but biases in the free troposphere remain unexplained.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

On the structure sensitivity of and CO coverage effects on formic acid decomposition on Pd surfaces

Using density functional theory calculations, the Pd-catalyzed vapor-phase formic acid decomposition was studied, with a focus on the structure sensitivity and CO coverage effects. A comprehensive reaction network was developed on both the (111) and (100) facets of Pd, at CO coverages of 0 and 5/9 monolayer (ML). Pd(100) was determined to be more reactive than Pd(111) at both CO coverages. The introduction of 5/9 ML CO decreased the activity of both facets significantly, due to destabilization of the surface intermediates and transition states on the CO-decorated surfaces. Three reaction pathways were explored on the clean surfaces: the formate (HCOO) pathway, the carboxyl (COOH) pathway leading to the formation of CO 2 , and the COOH pathway leading to the formation of CO (COOH→CO). Based on the DFT-derived energetics alone, it appears that all three pathways contribute to the reaction on clean Pd, whereas the presence of 5/9 ML of CO inhibits the HCOO pathway on both facets and favors the COOH→CO pathway on the (111) facet, but the COOH→CO 2 one on the (100) facet. Moreover, at high CO coverages, alternative spectator CO-assisted adsorbate decomposition pathways were discovered, which could potentially play a role in formic acid decomposition on Pd catalysts under realistic reaction conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗