Dehydrogenation Rate Research Articles

Parallel Alkane Dehydrogenation Routes on Brønsted Acid and Reaction-Derived Carbonaceous Active Sites in Zeolites

Alkane dehydrogenation rates on acidic zeolites measured in the presence of co-fed H2 during initial contact with reactants solely reflect protolytic reactions at Bronsted acid sites, while rates m...

Increase in the dehydrogenation rates and hydrogen-storage capacity of Mg-graphene composites by adding nickel via reactive ball milling

Ni was added to increase the dehydrogenation rates of graphene-added Mg with a composition of 95 wt% Mg + 5 wt% graphene (named Mg-5graphene). For this, samples with a composition of 95 wt% Mg + 2.5 wt% Ni + 2.5 wt% graphene (named Mg-2.5Ni-2.5graphene) were prepared by ball milling in hydrogen. Mg-2.5Ni-2.5graphene had significantly higher initial hydrogenation and dehydrogenation rates, with significantly larger quantities of hydrogen absorbed and released over 60 min, than Mg-5graphene. Mg-2.5Ni-2.5graphene exhibited a very high effective hydrogen-storage capacity of approximately 7 wt% at the second cycle (n = 2). We believe that the increase in the Mg crystallite size, leading to a decrease in the grain boundaries, with cycling contributed partly to decreases in the hydrogenation and dehydrogenation rates as n increases. We attributed the partial transformation of graphene into C60 fullerene to the processing of reactive ball milling and the introduction of heat during cycling.

MoSe2 hollow nanospheres decorated with FeNi3 nanoparticles for enhancing the hydrogen storage properties of MgH2

The FeNi3, MoSe2 and MoSe2@FeNi3 hollow nano-spheres synthesized by wet chemical method are used for the first time to improve the hydrogen storage properties of the MgH2. The results show that they all possess excellent catalytic activity in the hydrogen desorption/sorption reactions of MgH2. Because of the synergistic catalytic effect of MoSe2 and FeNi3, the MoSe2@FeNi3 has the most outstanding catalytic effect. In detail, the onset dehydrogenation temperature of MgH2 is reduced from 310 °C to 194 °C, and its maximum dehydrogenation rate is increased by 19.8 times by the introduction of 10 wt% MoSe2@FeNi3. Furthermore, the 10 wt% MoSe2@FeNi3-doped MgH2 sample, 5.8 wt% H2 can be absorbed in 0.5 min at 150 °C. However, the un-doped MgH2 sample hardly absorbs hydrogen under the same conditions. The onset hydrogen absorption temperature of the composite is only 73 °C. More importantly, it has an excellent cycling stability. These improvements are because the in situ formed MgSe, Mo, Mg2Ni and Fe can serve as active species, and they as well as their homogeneous distribution on MgH2 matrix can remain stable during dehydrogenation/hydrogenation. In addition, the presence of Mg2Ni can convert MgH2 to an easier pathway of hydrogen absorption/desorption. These help to facilitate the hydrogen storage performance of MgH2.

Hydrogen storage performances, kinetics and microstructure of Ti1.02Cr1.0Fe0.7-xMn0.3Alx alloy by Al substituting for Fe

For achieving good economic and environmental benefit, capacity of hydrogen storage alloys plays an important role in high-pressure-metal-hydride system of refueling station. Hydrogen storage characteristics of Ti1.02Cr1.0Fe0.7-xMn0.3Alx (0 ≤ x ≤ 0.1) alloys with main C14 structure were analyzed by Pressure-Composition-Temperature, XRD, HRTEM, SEM, EDS, ICP and XPS measurements, which were prepared by plasma arc melting and subsequent heat treatment. When Al content is lower than 0.05, it can improve the hydrogen reversible storage capacity from 1.58 to 1.65 wt% at 233 K. The pulverization resistances are enhanced by addition of Al (Al content: 0.05, 0.1), and the ductile fractures appear on the particle surfaces. Based on kinetic analysis, the dehydrogenation rates are fast with low activation energies between 7.4 and 9.9 kJ/mol. The mechanism for Al effecting the capacity is that, the big size effect dominates the capacity increase as Al content less than 0.05. Otherwise, higher Al2O3 content covering on the particles surface deteriorate hydrogen storage capacity as Al content exceeding 0.05. Among them, Ti1.02Cr1.0Fe0.68Mn0.3Al0.02 alloy has the best comprehensive properties for high-pressure metal hydride system in hydrogen refueling station. How to utilize the alloy to assemble the compressor and measure the toxicity resistance to impurity gas in H2 may be the future work.

Enhancing catalytic activity of rhodium towards methanol electro-oxidation in both acidic and alkaline media by alloying with iron

The methanol electrooxidation catalysts in the form of Rh and FeRh thin films were prepared by magnetron sputtering deposition. To activate the FeRh catalyst, the as-prepared FeRh films were cycled in 0.1 M HClO4 electrolyte in potential window from −0.25 V to 0.8 V (vs. Ag/AgCl). The dissolution of Fe atoms during the cycling leads to the formation of Rh-skeleton surface. Obtained FeRh catalysts exhibit significantly enhanced activity to methanol electrooxidation in both acidic and alkaline environments comparing to pure Rh catalyst. The optimal concentration of Fe is found to be 50%. Electrochemical impedance spectroscopy investigations show the higher rate of methanol dehydrogenation as well as better tolerance to CO intermediates poisoning of the FeRh catalysts. This study demonstrates that Rh-based catalysts can be considered as alternative to Pt-based catalysts.

Improvement of the Hydrogen-Release Features of Mg-Graphene Composite by Adding Nickel via Reactive Ball Milling

The dehydrogenation rates of graphene-added Mg (named Mg-5graphene) were very low at 573 K and 593 K. Ni was added to increase the dehydrogenation rates of graphene-added Mg. Samples (designated as Mg-2.5Ni-2.5graphene) with a composition of 95 wt% Mg + 2.5 wt% Ni + 2.5 wt% graphene were prepared by milling in hydrogen (reactive ball milling). Mg-2.5Ni-2.5graphene had significantly higher initial hydrogenation and dehydrogenation rates and much greater amounts of hydrogen absorbed and released after 60 min, Ha (60 min) and Hd (60 min), than Mg-5graphene. The addition of Ni lowered the magnesium hydride decomposition temperature from 683 K to 581 K. The activation of Mg-2.5Ni-2.5graphene was finished after the second hydrogenation-dehydrogenation cycle (n=2). Mg-2.5Ni-2.5graphene had a very high efficient capacity of stored hydrogen (the amount of hydrogen absorbed after 60 min) higher than 7 wt% (7.07 wt% at 573 K in 12 bar H2 at n=1). At n=1, the quantities of hydrogen released by Mg-2.5Ni-2.5graphene were 0.26 wt% H after 2.5 min and 3.34 wt% H after 60 min at 573K in 1.0 bar H2. (Received June 28, 2019; Accepted August 20, 2019)

Increasing the Hydrogenation and Dehydrogenation Rates of Magnesium by Incorporating CMC(Na) (Carboxymethylcellulose-Sodium Salt) and Nickel.

Samples with compositions of 95 wt% Mg + 5 wt% CMC(Na) [carboxymethylcellulose, sodium salt, {C6H7O₂(OH)x(C₂H₂O₃Na)y}n] [named Mg-5CMC(Na)] and 90 wt% Mg + 10 wt% CMC(Na) [named Mg-10CMC(Na)] were prepared via milling in hydrogen (hydride-forming milling). Mg-5CMC(Na) and Mg-10CMC(Na) had very high hydrogenation rates but low dehydrogenation rates. Adding Ni to Mg is known to increase the hydrogenation and dehydrogenation rates of Mg. We chose Ni as an additive to increase dehydrogenation rates of Mg-5CMC(Na) and Mg-10CMC(Na). A sample with a composition of 90 wt% Mg + 5 wt% CMC + 5 wt% Ni [named Mg-5Ni-5CMC(Na)] was prepared via hydride-forming milling. The activation of Mg-5Ni-5CMC(Na) was completed at the third hydrogenation-dehydrogenation cycle (N ═ 3). Mg-5Ni-5CMC(Na) had an effective hydrogen-storage capacity (the quantity of hydrogen absorbed for 60 min) of 5.83 wt% at 593 K in 12 bar hydrogen at N ═ 3. Mg-5Ni-5CMC(Na) released 2.73 wt% H for 10 min and 4.61 wt% H for 60 min at 593 K in 1.0 bar hydrogen at N ═ 3. Mg-5Ni-5CMC(Na) dehydrogenated at N ═ 4 contained Mg and small amounts of MgO, β-MgH₂, Mg₂Ni, and Ni. Hydride-forming milling of Mg with CMC and Ni and Mg₂Ni formed during hydrogenation-dehydrogenation cycling are believed to have increased the dehydrogenation rates of Mg-5CMC(Na) and Mg-10CMC(Na). As far as we know, this study is the first in which a polymer CMC(Na) and Ni were added to Mg via hydride-forming milling to improve the hydrogenation and dehydrogenation rates of Mg.

High resolution energy-time of flight spectrometer: Dehydrogenation of fluorene cation as case study

Testing and performance validation of a new multipurpose time-of-flight mass spectrometer followed by an energy analyzer is presented. The instrument with high mass and energy resolution is primarily designed to study cations of polycyclic aromatic hydrocarbons (PAHs) and their dehydrogenation process. The energy correlated time-of-flight measurement is supplemented by Monte Carlo simulation to probe the dehydrogenation process in a relatively small PAH cation. The experiment is carried out on fluorene+ on a timescale of several microseconds. Fluorene cations with high internal energies were produced using UV multiphoton ionization. Specific n-photon processes leading to ionization as well as H-loss reaction were identified. The average value of dehydrogenation rate is estimated by fitting the measured data to the outcome of simulations. The quantification of H loss decay rate is in agreement with previously reported decay rate measurement. This corresponds to the internal energy available by inner valence electron emission caused by three photon process. The effectiveness of the instrument to access a range of decay rates (103–107 s−1) in a single measurement is demonstrated.

Solid-Phase Hydrogen Storage Based on NH3BH3-SiO2 Nanocomposite for Thermolysis

Current H2-proton exchange membrane fuel cell systems available for commercial applications employ heavy and high-risk physical hydrogen storage containers. However, these compressed or liquefied H2-containing cylinders are only suitable for ground-based electric vehicles, because although highly purified H2 can be stored in a cylinder, it is not compatible with unmanned aerial vehicles (UAVs), which require a lighter and more stable energy source. Here, we introduce a chemical hydrogen storage composite, composed of ammonia borane (AB) as a hydrogen source and various heterogeneous catalysts, to elevate the thermal dehydrogenation rate. Nanoscale SiO2 catalysts with a cotton structure dramatically increase the hydrogen evolution rate on demand, while simultaneously lowering the startup temperature for AB thermolysis. Results show that the dehydrogenation reaction of AB with a cotton-structured SiO2 nanocatalyst composite occurs below 90°C, the reaction time is less than a minute, and the hydrogen generation yield is over 12 wt%, with an activation energy of 63.9 kJ·mol-1.

Coupled inter-site reaction and diffusion: Rapid dehydrogenation of silicon vacancies in natural olivine

Abstract Natural olivine from Zermatt (Switzerland) and Almklovdalen (Norway) were dehydrogenated at 1 bar, 517–1009 °C at various oxygen fugacity conditions. Following experiments, H contents (either bulk, or core-rim profiles) were measured using Fourier transform infrared spectroscopy, and spectra were resolved into Gaussian peaks. The starting olivine contained ∼150 and ∼10 wt. ppm H2O for the Zermatt and Almklovdalen samples respectively, but importantly the initial H distribution in both corresponded to defects with 4H+ occupying Si vacancies. Experiments in pure forsterite Padron-Navarta and Hermann, (2017) showed that this defect diffuses very slowly relative to other H diffusion mechanisms in olivine. Conversely, we show that, in the Almklovdalen samples, H loss from the Si-vacancy defect can be extremely rapid, and approaches the fastest known mechanism of H diffusion (proton-polaron diffusion) in olivine. The rate of dehydrogenation from the Zermatt olivine is slightly slower, more consistent with the diffusivity of hydrogenated M-site vacancies. The sum of all defects, along with the integrated area of the main Si vacancy peak (3612 cm−1) generally shows simple diffusive behaviour, whereas profiles (or maps) resolved into individual peaks reveal complex profile shapes not consistent with a simple out-diffusion mechanism. This behaviour can be modeled as a combination of inter-site reaction and diffusion, whereby H leaves the tetrahedral site, moves into a faster diffusion pathway, then rapidly exits the crystal. The rate of H loss from, or gain into, olivine can therefore be either diffusion limited, reaction limited, or a combination of the two. This may explain current discrepancies between experiments conducted under different conditions and between experimental and natural data, including the recent observation that H stored in Si vacancies in metamorphic olivine may be retentive over millions of years, despite the capability to diffuse rapidly via a different mechanism.

Influence of Pt particle size and reaction phase on the photocatalytic performances of ultradispersed Pt/TiO2 catalysts for hydrogen evolution

Pt/TiO2 photocatalysts were prepared by incipient wetness impregnation followed by oxidative and/or reductive thermal treatments. By varying the TiO2 form (commercial P25 and P90, and homemade shape-controlled), the Pt loading (0.2–1 wt% Pt) and the treatment temperature (200–600 °C), it has been possible to tune the Pt cluster size. An increase in the ethanol dehydrogenation rate under ultraviolet irradiation as the Pt cluster average diameter decreases from 17 to 9 Å is suggested by our data. Whereas pre-reduction in H2 leads to Pt clusters, pre-calcination in air leads to atomically dispersed cationic Pt species. The former are more active and stable than the latter. This conclusion is valid both in gas- and liquid-phase reaction conditions for given TiO2 type and Pt loading. The activity results are consistent with a recent theoretical work showing that 1 nm is an optimal Pt cluster size for favoring both photoelectron transfer from TiO2 to Pt and hydrogen coupling on Pt. The best catalytic performance is obtained in gas phase for pre-reduced 0.2 wt% Pt/TiO2-P90, with an H2 production rate of 170 mmol h−1 gcat−1.

Amine-functionalized sepiolite: Toward highly efficient palladium nanocatalyst for dehydrogenation of additive-free formic acid

Formic acid has recently come to be considered as a promising material for chemical storage of hydrogen. To date, highly efficient and low-cost heterogeneous catalysts for formic acid dehydrogenation without additive under mild conditions are still limited. In this work, we employed amine-functionalized sepiolite, a typical natural clay mineral with fibrous structure, as support to synthesize a nanocatalyst by the simple impregnation-reduction method. The amine groups on amine functionalized sepiolite support are shown to significantly reduce the average size of Pd nanoparticles (from 7.60 to 2.80 nm) as well as provide a synergistic effect with the Pd nanoparticles, which boosts the rate of additive-free formic acid dehydrogenation (initial turnover frequency (TOF) values of 5587 h−1 at 60 °C, equal to or even better than the most active heterogeneous catalysts). Compared to current catalyst systems, this catalyst can lead to a brighter prospect of cost-efficient heterogeneous catalysts for formic acid dehydrogenation.

Evidences for Different Reaction Sites for Dehydrogenation and Dehydration of Ethanol over Vanadia Supported on Titania

Vanadia supported on titania were prepared with increasing vanadia loadings up to 20 wt % to study the effect of the vanadia loading on catalytic reactivity. A competitive decomposition of ethanol into ethylene (dehydration) and acetaldehyde (dehydrogenation) over the catalyst occurs over the vanadia supported on TiO2. Dehydrogenation is generally favored over dehydration over a wide range of the vanadia loadings up to 20 wt % due to a lower energy barrier for the dehydrogenation channel. Both dehydration and dehydrogenation rates are enhanced in proportion to the vanadia loadings up to about 2 wt %. At higher vanadia loadings (>2 wt %), however, the dehydration rate decreases while the dehydrogenation rate saturates. X‐ray photoelectron spectroscopic analysis reveals that reduced V and Ti species are formed at the low vanadia contents and act as strong dissociative adsorption sites for H2O, while extended VOx clusters as well as three‐dimensional V2O5 islands formed at high vanadia loadings prevent the formation of such sites. Thus, the observed difference between the two reaction channels can be explained from the structural transition of the vanadia overlayers from highly dispersed small VOx clusters into larger polyvanadates or islands. At low vanadia loadings (<2 wt %), both the edge sites and the surface sites of the small VOx clusters grow in proportion to the loadings as the number of the clusters increases. Thus, both reaction channels are enhanced as well. At higher vanadia loadings (>2 wt %), however, the transformation into larger islands reduces the edge sites or the boundaries between the clusters and TiO, not the surface area. This implies that the active sites for the dehydrogenation are on the surfaces of the vanadia overlayers, while those for the dehydration are on the boundaries between the VOx and TiO2. Our results provide an additional insight into the active sites for dehydration and dehydrogenation reactions over the titania‐supported vanadia catalysts.

A small pilot reactor containing active MgTi–based hydrides at low operational temperatures

This study was investigated to utilize innovatively oil-free diaphragm pump to forcibly desorb the hydrogen from the small pilot MgH2–TiH2 based hydride reactor below the theoretical temperature of 278 °C. Active MgH2-0.1TiH2 composites were prepared using ball milling. Their hydrogenation performances at 25–300 °C were measured under a constant H2 flow mode using a modified Sieverts apparatus. The dehydrogenation rates at 250–350 °C with or without diaphragm pump were investigated to examine whether the pilot reactors could be integrated with a proton exchange membrane fuel cell (PEMFC) for power generation. At a H2 flow rate of 25 ml min−1 g−1, the reactors exhibited excellent hydrogenation, achieving gravimetric hydrogen storage capacities of 2.9–5.2 wt% (excluding the weight of the reactors) at 25–300 °C after 22 min. All hydrided MgTi–based reactors could be dehydrogenated at 250 °C at an average rate of 5 ml min−1 g−1 under vacuum. This is the first demonstration of Mg-based reactors that were hydrogenated at 100 °C and dehydrogenated at 250 °C to power a small PEMFC, yielding a measured conversion efficiency of 18%.

Ternary amide-hydride system: A study on LiAl(NH2)4-LiAlH4 interaction

LiAl(NH2)4 is a ternary amide that readily decomposes to release ammonia at temperatures as low as ∼ 90 °C. Owing to such instability as compared to binary amides, we hypothesize that the dehydrogenation mechanism involving ternary amide-hydride interaction would be significantly different from those of binary metal amide-hydride interaction. Therefore, in this study, interaction of LiAl(NH2)4 and LiAlH4 has been investigated by means of mechanical milling and thermal method. It was found that dehydrogenation occurred spontaneously during the milling process and the rate of dehydrogenation increased with increasing amount of LiAlH4, suggesting an ion migration mediated dehydrogenation. As reaction progressed, the formation of Li3AlH6 as an intermediate was detected and a total of 8 equiv. of H2 (7.5 wt%) can be released, forming LiH and AlN as the final product. In contrast, heating the homogenously ground LiAl(NH2)4 and LiAlH4 sample resulted in the release of NH3 at low temperatures, indicating that NH3 mediation would take place in case of dehydrogenation. Further increase in temperature resulted in a rapid release of hydrogen from the interaction of the LiAl(NH)2 and LiAlH4. It was also found that hydride with higher basicity is required to trigger amide-hydride interaction for dehydrogenation at low temperatures.

An efficient mechanochemical synthesis of alpha-aluminum hydride: Synergistic effect of TiF3 on the crystallization rate and selective formation of alpha-aluminum hydride polymorph.

α-AlH3 is one of the most promising hydrogen storage materials due to its high gravimetric hydrogen capacity and low dehydriding temperature. In present work, a convenient and cost-efficient solid-state mechanochemical reaction is proposed to obtain α-AlH3 nano-composite. With the addition of TiF3, α-AlH3 nano-composite was formed in a short period by milling of LiH and AlCl3. Based on XRD and NMR results, the average grain size of the α-AlH3 in the nano-composite was 45 nm. The reaction pathway as well as the synergistic effect of TiF3 on the solid state reaction between LiH and AlCl3 were confirmed. In the α-AlH3/LiCl nano-composite, TiF3 reduced the temperature of dehydriding reaction and improved dehydrogenation rate of α-AlH3. Within the temperature range between 80 and 160 °C, dehydrogenation of the as-milled α-AlH3 nano-composite showed fast kinetics. At 160 °C, a maximum hydrogen desorption of 9.92 wt% was obtained within 750 s, very close to the theoretical hydrogen capacity of α-AlH3.

Propanol Amination over Supported Nickel Catalysts: Reaction Mechanism and Role of the Support

Ni-supported hydroxyapatite catalyst (Ni/HAP) was characterized and evaluated for propanol amination to propylamine at 423 K. The reaction proceeds via dehydroamination, a process that involves sequential dehydrogenation, condensation, and hydrogenation. Kinetic and isotopic studies indicate that α-H abstraction from propoxide species limits the rate of the dehydrogenation step and hence the overall rate of reaction. The rate of propanol dehydrogenation depends on the composition of the support and on the concentration of Ni sites located at the interface between Ni nanoparticles and the support. Ni/HAP is an order of magnitude more active than Ni/SiO2 and displays a higher selectivity toward the primary amine. The superior performance of Ni/HAP is attributed to the high density of basic sites on HAP, which are responsible for stabilizing alkoxide intermediates and suppressing the disproportionation and secondary amination of amines.

Improving the hydrogen storage performance of lithium borohydride by Ti3C2 MXene

Two-dimensional layered material of Ti3C2 has been used to improve the hydrogen desorption properties of LiBH4. The results of temperature-programmed dehydrogenation (TPD) and isotherm dehydrogenation (TD) demonstrate that adding the Ti3C2 contributes to the hydrogen storage performance of LiBH4. The dehydrogenation temperature decreases and the dehydrogenation rate increases with increasing the adding amounts of Ti3C2. The onset dehydrogenation temperature of LiBH4 + 40 wt% Ti3C2 composite is 120 °C and approximately 5.37 wt% hydrogen is liberated within 1 h at 350 °C. Furthermore, the activation energy of LiBH4 + wt.% Ti3C2 is also greatly reduced to 70.3 kJ/mol, much lower than that of pure LiBH4. The remarkable dehydrogenation property of the LiBH4+ 40 wt% Ti3C2 may be due to the layered active Ti-containing Ti3C2 and the high surface area of MXene.

Mechanism and Kinetics of Propane Dehydrogenation and Cracking over Ga/H-MFI Prepared via Vapor-Phase Exchange of H-MFI with GaCl3.

In this study, the mechanism and kinetics of C3H8 dehydrogenation and cracking are examined over Ga/H-MFI catalysts prepared via vapor-phase exchange of H-MFI with GaCl3. The present study demonstrates that [GaH]2+ cations are the active centers for C3H8 dehydrogenation and cracking, independent of the Ga/Al ratio. For identical reaction conditions, [GaH]2+ cations in Ga/H-MFI exhibit a turnover frequency for C3H8 dehydrogenation that is 2 orders of magnitude higher and for C3H8 cracking, that is 1 order of magnitude higher than the corresponding turnover frequencies over H-MFI. C3H8 dehydrogenation and cracking exhibit first-order kinetics with respect to C3H8 over H-MFI, but both reactions exhibit first-order kinetics over Ga/H-MFI only at very low C3H8 partial pressures and zero-order kinetics at higher C3H8 partial pressures. H2 inhibits both reactions over Ga/H-MFI. It is also found that the ratio of the rate of dehydrogenation to the rate of cracking over Ga/H-MFI is independent of C3H8 and H2 partial pressures but weakly dependent on temperature. Measured activation enthalpies together with theoretical analysis are consistent with a mechanism in which both the dehydrogenation and cracking of C3H8 proceed over Ga/H-MFI via reversible, heterolytic dissociation of C3H8 at [GaH]2+ sites to form [C3H7-GaH]+-H+ cation pairs. The rate-determining step for dehydrogenation is the β-hydride elimination of C3H6 and H2 from the C3H7 fragment. The rate-determining step for cracking is C-C bond attack of the same propyl fragment by the proximal Brønsted acid O-H group. H2 inhibits both dehydrogenation and cracking over Ga/H-MFI via reaction with [GaH]2+ cations to form [GaH2]+-H+ cation pairs.

Two-step catalytic dehydrogenation of formic acid to CO2 via formaldehyde

Formic acid has been decomposed into hydrogen and carbon dioxide through a two-step process involving the formation of formaldehyde. This allows the formation of carbon dioxide and hydrogen in two different steps, negating the need for gas separation. A novel system for the catalytic disproportionation of formic acid into formaldehyde and carbon dioxide was thus far developed using monoclinic bismuth chromate hydroxide proto-catalyst, m-Bi(OH)CrO4. The catalytically active species, BiCrO4, was isolated and its activity assessed for thermal disproportionation of formic acid under mild conditions (200–300 °C, tube furnace). A maximum formaldehyde production rate of 0.065 mmol/mmol catalyst/hour was observed using bismuth chromate at 250 °C. The formaldehyde produced through this method was selectively dehydrogenated to formate by an IrCl3 catalyst at room temperature under basic conditions, with a dehydrogenation rate of 20.1 mmol of hydrogen/mmole catalyst/hour. This completes a step-by-step and yet efficient cycle of formic acid dehydrogenation.