Hydrogen adsorption in transition metal carbon nano-structures

Abstract

Templated microporous carbons were synthesized from metal impregnated zeolite Y templates. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were employed to characterize morphology and structure of the generated carbon materials. The surface area, micro-and meso-pore volumes, as well as the pore size distribution of all the carbon materials were determined by N 2 adsorption at 77 K and correlated to their hydrogen storage capacity. All the hydrogen adsorption isotherms were Type 1 and reversible, indicating physisorption at 77 K. Most templated carbons show good hydrogen storage with the best sample Rh-C having surface area 1817 m 2 /g and micropore volume 1.04 cm 3 /g, achieving the highest as 8.8 mmol/g hydrogen storage capacity at 77 K, 1 bar. Comparison between activated carbons and synthesized templated carbons revealed that the hydrogen adsorption in the latter carbon samples occurs mainly by pore filling and smaller pores of sizes around 6 Å to 8 Å are filled initially, followed by larger micropores. Overall, hydrogen adsorption was found to be dependent on the micropore volume as well as the pore-size, larger micropore volumes showing higher hydrogen adsorption capacity.

Synthesis and Electrochemical Study of Pd-Based Trimetallic Nanoparticles for Enhanced Hydrogen Storage

“…The spillover effect is well-known in the field of heterogeneous catalysis, and it has been largely debated recently in relation with hydrogen storage in adsorbed states. ,− Hydrogen spillover is commonly described as the dissociative adsorption of H 2 on metal catalyst particles, followed by the migration of H atoms to the support and diffusion of the atoms on the support. , Attaining enhanced hydrogen storage on adsorbents such as activated carbon may be achieved by exploiting hydrogen spillover at the gas–solid interface. , To assess the hydrogen uptake enhancement of the PAC200 supported PdAg 10 Cd 10 nanoparticles at the electrode–electrolyte interface, we further studied the electrochemical behaviors of the PAC200 support in the absence of any metal catalyst and studied the PdAg 10 Cd 10 catalysts in the absence of the PAC200 support. Supporting Information (SI) Figure S1 presents the CV of the PAC200 sample recorded in 0.5 M H 2 SO 4 at a scan rate of 5 mV/s; no hydrogen sorption and desorption peak appeared, indicating the necessary presence of a catalyst.…”

“…The enhancement of hydrogen storage on adsorbents such as activated carbon may be achieved by exploiting hydrogen spillover. − The dispersal of metal catalysts onto the surface allows for the dissociation of dihydrogen molecules, leading to the subsequent spillover of hydrogen atoms to carbon and, thus in turn, increasing the amount of hydrogen sorbed. , As a metal catalyst, palladium exhibits a good compromise between suitable dissociation abilities and low adherence strengths for use in hydrogen spillover. By alloying Pd with other metals such as Ag and Cd, the phenomena may be further enhanced. − In the present study, we have investigated the electrochemical hydrogen adsorption capabilities of activated carbon supported nanoparticles at room temperature.…”

Influence of the pore size in multi-walled carbon nanotubes on the hydrogen storage behaviors

“…It was also found that the hydrogen storage capacity was simply proportional to specific surface areas of the carbon at pressure below 100 bar; meanwhile, at the pressures above 100 bar, the uniform micropores with a diameter of 1.2 nm in carbons played a more important role in capacity than the specific surface area. Webley et al [39] studied the hydrogen storage in transition metal loaded zeolite-templated carbons. The best sample (Rh-loaded carbon) having surface area 1817 m 2 /g and micropore volume 1.04 cm 3 /g showed the highest as 1.77 wt% hydrogen storage capacity at 77 K and 1 bar.…”

Laser assisted fabrication of porous polymer MEMS with nano structured additives

“…Multilayers with giant magnetoresistance, which could be realized in the layers interleaving ferromagnetic and nonmagnetic metals, have attractive applications [1][2][3]. With the decrease of particle sizes from the micro-to the nano-level, the specific surface area to volume ratios grows and, consequently, the chemical activity of nanoparticles follows to this behavior.…”