Hydrogen from formic acid through its selective disproportionation over sodium germanate--a non-transition-metal catalysis system

Amine-Functionalized Natural Halloysite Nanotubes Supported Metallic (Pd, Au, Ag) Nanoparticles and Their Catalytic Performance for Dehydrogenation of Formic Acid

In today’s age of resource scarcity, the low-cost development and utilization of renewable energy, e.g., hydrogen energy, have attracted much attention in the world. In this work, cheap natural halloysite nanotubes (HNTs) were modified with γ-aminopropyltriethoxysilane (APTES), and the functionalized HNTs were used as to support metal (Pd, Au, Ag) catalysts for dehydrogenation of formic acid (DFA). The supports and fabricated catalysts were characterized with ICP, FT-IR, XRD, XPS and TEM. The functional groups facilitate the anchoring of metal particles to the supports, which brings about the high dispersion of metallic particles in catalysts. The catalysts show high activity against DFA and exhibit selectivity of 100% toward H2 at room temperature or less. The interactions between active centers and supports were investigated by evaluation and comparison of the catalytic performances of Pd/NH2-HNTs, PdAg/NH2-HNTs and PdAu/NH2-HNTs for DFA.

In situ generated electron-deficient metallic copper as the catalytically active site for enhanced hydrogen production from alkaline formaldehyde solution

Low-cost copper-based catalysts have attracted great interest as they are able to accelerate hydrogen evolution from formaldehyde solution at room temperature.

CO2-based hydrogen storage – formic acid dehydrogenation

Changing demands on the energy landscape are causing the need for sustainable approaches. The shift toward alternative, renewable energy sources is closely associated with new demands for energy storage and transportation. Besides storage of electrical energy, also storage of energy by generating and consuming hydrogen (H2) is possible and highly attractive. Notably, both secondary energy vectors, electric energy and hydrogen, have practical advantages so that one should not ask “which one is better?” but “which one fits better the specific application?”

Molecular hydrogen can be stored reversibly in form of formic acid (FA, HCOOH). In the presence of suitable catalysts, FA can be selectively decomposed to hydrogen and carbon dioxide (CO2). A CO2-neutral hydrogen storage cycle can be achieved when carbon dioxide serves as starting material for the production of the FA. Examples of CO2 hydrogenation to FA are known in the literature. Herein, the formal reverse reaction, the decomposition of FA to H2 and CO2 by different catalyst systems is reviewed and selected examples for reversible storage applications based on FA as hydrogen storage compound are discussed.

Biocatalysis for the application of CO2 as a chemical feedstock

Biocatalysts, capable of efficiently transforming CO2 into other more reduced forms of carbon, offer sustainable alternatives to current oxidative technologies that rely on diminishing natural fossil-fuel deposits. Enzymes that catalyse CO2 fixation steps in carbon assimilation pathways are promising catalysts for the sustainable transformation of this safe and renewable feedstock into central metabolites. These may be further converted into a wide range of fuels and commodity chemicals, through the multitude of known enzymatic reactions. The required reducing equivalents for the net carbon reductions may be drawn from solar energy, electricity or chemical oxidation, and delivered in vitro or through cellular mechanisms, while enzyme catalysis lowers the activation barriers of the CO2 transformations to make them more energy efficient. The development of technologies that treat CO2-transforming enzymes and other cellular components as modules that may be assembled into synthetic reaction circuits will facilitate the use of CO2 as a renewable chemical feedstock, greatly enabling a sustainable carbon bio-economy.

Metal-free dehydrogenation of formic acid to H2 and CO2 using boron-based catalysts

The decomposition of formic acid to H₂ and CO₂ under metal-free conditions has been unveiled using dialkylborane derivatives as catalysts.

Formic acid is at the crossroads of novel sustainable energy strategies because it is an efficient H₂ carrier. Yet, to date, its decomposition to H₂ relies on metal-based catalysts. Herein, we describe the first metal-free catalysts able to promote the dehydrogenation of formic acid. Using dialkylborane derivatives, HCOOH is decomposed to H₂ and CO₂ in the presence of a base with high selectivity. Experimental and computational results point to the involvement of bis(formyloxy)borates as key intermediates in the C–H bond activation of a formate ligand.