Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts

Abstract

Polymer electrolyte membrane fuel cells (PEMFCs) running on hydrogen are attractive alternative power supplies for a range of applications, with in situ release of the required hydrogen from a stable liquid offering one way of ensuring its safe storage and transportation before use. The use of methanol is particularly interesting in this regard, because it is inexpensive and can reform itself with water to release hydrogen with a high gravimetric density of 18.8 per cent by weight. But traditional reforming of methanol steam operates at relatively high temperatures (200-350 degrees Celsius), so the focus for vehicle and portable PEMFC applications has been on aqueous-phase reforming of methanol (APRM). This method requires less energy, and the simpler and more compact device design allows direct integration into PEMFC stacks. There remains, however, the need for an efficient APRM catalyst. Here we report that platinum (Pt) atomically dispersed on α-molybdenum carbide (α-MoC) enables low-temperature (150-190 degrees Celsius), base-free hydrogen production through APRM, with an average turnover frequency reaching 18,046 moles of hydrogen per mole of platinum per hour. We attribute this exceptional hydrogen production-which far exceeds that of previously reported low-temperature APRM catalysts-to the outstanding ability of α-MoC to induce water dissociation, and to the fact that platinum and α-MoC act in synergy to activate methanol and then to reform it.

Potential‐Cycling Synthesis of Single Platinum Atoms for Efficient Hydrogen Evolution in Neutral Media

“…The energy dispersive X‐ray spectroscopic (EDS) result in Figure 2 d shows the presence of Pt in the NTs (see Figure S2 for the EDS maps of Co, Mn, O, P, and Ni), and the Pt weight percentage is 1.6 %. AR HAADF imaging performed by aberration‐corrected scanning TEM (STEM) indicates that a plenty of single Pt atoms are well dispersed on the NTs (Figures 2 e and Figure S3), similar to those reported,10a,10c, 12, 13, 18 and no Pt crystal grains/particles are found. Further, the electron diffraction pattern in Figure 2 f demonstrates that the NTs contain the crystal grains of Ni(OH) 2 , CoP and Co 2 P, but no diffraction spots from Pt crystals are present, according to the standard crystallographic data of Joint Committee on Powder Diffraction Standards.…”

Atomically Dispersed Copper–Platinum Dual Sites Alloyed with Palladium Nanorings Catalyze the Hydrogen Evolution Reaction

“…[6] One promising approach involves reducing the particle size of Pt to an anometer or atomic level, with the aim to increase the number of surface active sites. [7][8][9][10][11] Forexample,very small quantities of isolated Pt atoms show outstanding hydrogen-production activity in the low-temperature aqueous-phase reforming of methanol. [8] Isolated single Pt atoms and clusters supported on nitrogen-doped graphene nanosheets exhibit excellent HER activity.…”

Engineering oxygen vacancy on rutile TiO2 for efficient electron-hole separation and high solar-driven photocatalytic hydrogen evolution

“…Hydrogen is considered as an environmental renewable energy source due to its high energy density and environment friendly [1]. Hence, photocatalytic hydrogen production attracts much more attention recently [2][3][4].…”