Acid‐ and Base‐Catalyzed Hydrolytic Hydrogen Evolution from Diboronic Acid

Abstract

The efficient production of H2 from hydrogen‐rich sources, particularly from water, is a crucial task and a great challenge, both as a sustainable energy source and on the laboratory scale for hydrogenation reactions. Herein, a facile and effective synthesis of H2 and D2 from only acid‐ or base‐catalyzed metal‐free hydrolysis of B2(OH)4, a current borylation reagent, has been developed without any transition metal or ligand. Acid‐catalyzed H2 evolution was completed in 4 min, whereas the base‐catalyzed process needed 6 min. The large kinetic isotopic effects for this reaction with D2O, deuteration experiments and mechanistic studies have confirmed that both H atoms of H2 originate from water using either of these reactions. This new, metal‐free catalytic system holds several advantages, such as high efficiency, simplicity of operation, sustainability, economy, and potential further use.

Mechanistic insights into H2 evolution via water splitting at the expense of B2(OH)4: a theoretical study

“…Since 2020, our group successively reported highly efficient H 2 production upon water splitting at the expense of B 2 (OH) 4 (eqn (1)), which is a common borylation reagent [60][61][62][63][64][65][66][67][68] catalysed by acid, base or metal nanoparticles. 69,70 Experiments using D 2 O in place of H 2 O including the kinetic isotope effect and tandem reaction have confirmed that both H atoms of produced H 2 are only provided by water. Although their mechanisms, based on some control experiments, were proposed in our previous work, theoretical investigation of mechanistic insights into H 2 evolution from water splitting at the expense of B 2 (OH) 4 is still highly desirable.…”

Mn‐Modified Graphitic Carbon Nitride‐Supported Bimetallic PtNi Nanoparticles for Hydrogen Generation from Hydrous Hydrazine

“…[1,2] Hydrogen, producing water as the only byproduct, is green and sustainable with high energy density and it has been a globally accepted clean energy source. [3][4][5][6] However, hydrogen exists stably in a gaseous state at room temperature, which greatly hinders its storage and transportation. Therefore, searching clean and valid hydro-gen storage technologies remain the crucial issue for largescale applications of hydrogen.…”

“On–Off” Control for On-Demand Hydrogen Production from the Dehydrogenation of Formic Acid

“…Sustainable and green energy alternatives, − including solar power, wind power, hydropower, tidal power, biopower, and hydrogen energy, − have been attracting a considerable amount of interest as a result of the gradual conventional fossil fuel consumption and increasingly severe environmental pollution after entering the 21st century. − Among them, hydrogen (H 2 ) is comprehensively deemed as one of the most potential energy alternatives due to its merits of high energy capacity (142 MJ/kg, triple-fold as that of petrol), − abundant reserves in the earth, and efficiency with environmentally friendly nature, − as well as its classic application in the proton exchange membrane fuel cells. − In this context, increasing attention has been paid to on-demand H 2 evolution from formic acid (FA) as a green and promising H 2 storage and production material because of its excellent volumetric (53.4 g/L) and gravimetric (4.4 wt %) hydrogen capacities, ease of handling and transporting, stability and nontoxicity at room temperature, as well as simple regeneration from cheap and abundant biomass. − Hence, a myriad of homogeneous and heterogeneous catalytic systems are successfully developed for facilitating FA dehydrogenation (eq ) − and avoiding CO poisoning from FA dehydration (eq 2 ) in the on-demand in situ H 2 evolution. − In particular, AgPd bimetal nanostructures (core–shell or alloy) with controlled compositions and morphologies have played a vital role in H 2 evolution from FA because of their ligand effect and strain effect as well as superior catalytic activities. − For example, Lu group first reported a highly efficient robust solid catalyst of PdAg–CeO 2 /MC by anchoring amorphous CeO 2 -modified PdAg alloy onto porous ca...…”