Cu[Ni(2,3-pyrazinedithiolate)₂] Metal–Organic Framework for Electrocatalytic Hydrogen Evolution

Abstract

The application of metal–organic frameworks (MOFs) as electrocatalysts for small molecule activation has been an emerging topic of research. Previous studies have suggested that two-dimensional (2D) dithiolene-based MOFs are among the most active for the hydrogen evolution reaction (HER). Here, a three-dimensional (3D) dithiolene-based MOF, Cu­[Ni­(2,3-pyrazinedithiolate)2] (1), is evaluated as an electrocatalyst for the HER. In pH 1.3 aqueous electrolyte solution, 1 exhibits a catalytic onset at −0.43 V vs the reversible hydrogen electrode (RHE), an overpotential (η10 mA/cm2 ) of 0.53 V to reach a current density of 10 mA/cm2, and a Tafel slope of 69.0 mV/dec. Interestingly, under controlled potential electrolysis, 1 undergoes an activation process that results in a more active catalyst with a 200 mV reduction in the catalytic onset and η10 mA/cm2 . It is proposed that the activation process is a result of the cleavage of Cu–N bonds in the presence of protons and electrons. This hypothesis is supported by various experimental studies and density functional theory calculations.

Phosphine Oxide Porous Organic Polymers Incorporating Cobalt(II) Ions: Synthesis, Characterization, and Investigation of H2 Production

“…This suggested the catalytic HER activity of the Co@P1,3,4,6 derivatives, induced by the presence of cobalt in the inner cavities of the corresponding porous materials and most likely associated to Co­(II) reduction. The overpotentials to reach a current density of 1 mA·cm –2 were 0.68 V for Co@P4 Fe , 0.66 V for Co@P1 Fe and Co@P6 Fe , and 0.53 V for Co@P3 Li , relatively high compared to (i) other HER electrocatalysts working at neutral pH , (ii) related MOF , and COF ,, materials (working under kinetically more favorable strongly acidic or basic conditions), and (iii) the only reported noncarbonized POP-based material for electrochemical HER (containing intrinsically highly active Pt nanoparticles) . The high HER overpotentials of these cobalt-based materials could be tentatively explained either with the low density of catalytic sites, the low wettability, or the low electrical conductivity of the polymer materials.…”

Novel ditopic 2-mercaptothiazoles and their sodium salts: synthesis, structural diversity and luminescence

“…13 Among such ligands the most studied are benzenehexathiol 14 (BHT) and 2,3,6,7,10,11-triphenylenehexathiol 15 (THT) whose compounds are attractive due to high conductivity and H 2 -evolving activity in the hydrogen evolution reaction. 16…”

Pristine Metal–Organic Frameworks and their Composites for Renewable Hydrogen Energy Applications

“…[78] Besides that, the integration of active molecular complexes/photosensitizer units into the ligands of MOFs also holds great promise to enhance the performance of pristine MOFs for photocatalytic H 2 evolution via reducing the distance of photosensitizers and active sites and faster elec tron transfer. [130][131][132] Also, the high stability of metalloporphyrin complexes and their strong interactions with O 2 endow them as suitable candidates for ORR electrocatalysts. [133] For instance, Huang et al developed highly dense chain type porphyrinic MOF (PCN226) as electrocatalysts for ORR using redox active metalloporphyrin linker and Zroxide zigzag chains as metal nodes.…”