Bimetallic (Zn/Co) MOFs-Derived Highly Dispersed Metallic Co/HPC for Completely Hydrolytic Dehydrogenation of Ammonia–Borane

Abstract

The development of a highly efficient and secure system for hydrogen storage and delivery is currently imperative, yet has great challenges. Herein, a series of highly dispersed and small cobalt nanoparticles supported by MOF-derived hierarchically porous carbon were synthesized by employing a selective atom evaporated-isolation strategy with bimetal Co/Zn-MOF-74 used as sacrificial template. The formation of ultrasmall Co nanoparticles in the hierarchically porous carbon was largely due to the assistance of doped Zn atoms in Co/Zn-MOF-74 precursors, which restricted their agglomeration during pyrolysis. Detailed catalytic results indicated that both the mole ratio of Co/Zn and the pyrolysis temperature were crucial to modulate their dehydrogenation performance for ammonia–borane, of which the as-synthesized 30% Co/HPC catalyst pyrolyzed under 900 °C exhibited the highest catalytic activity. Furthermore, these Co/HPC catalysts also showed good structure stability and magnetically reusability, which, together with the superior activity, enabled them to hold great promise for practical applications.

Bimetallic metal–organic frameworks and their derivatives

“…[281][282][283][284] Bimetallic MOF-derived nanomaterials exhibit high catalytic performance for the release of hydrogen from chemical hydrogen storage materials such as ammonia borane (NH 3 BH 3 , AB) and lithium borohydride (LiBH 4 ). [285][286][287][288] Chen and co-workers fabricated porous cobalt phosphide supported by carbon-based nanoframeworks (CoP@CNFs), which was derived from Zn/Co-ZIF and was applied for hydrogen generation from AB. 286 Zn/Co-ZIF was calcined in air to get Zn-Co-O@CNF, followed by phosphidation using Na 2 H 2 PO 2 and further acid treatment to get CoP@CNFs.…”

Resolvation-Based Damage to Metal–Organic Frameworks and Approaches to Mitigation

“…Many potential MOF applications, including catalysis, , environmental remediation/pollutant capture, separations, and chemical sensing, rely on the material interacting with species in the liquid phase. In such cases, and particularly in the area of MOF catalysis, it is the general practice for MOFs to be synthesized solvothermally, activated via solvent removal, and then resolvated via direct immersion in the relevant solvent. − We have recently outlined best practices for avoiding framework collapse during MOF activationlow-surface-tension activation solvents such as hexane, perfluoropentane, and supercritical CO 2 (scCO 2 ) have been found to be the least harmful to fragile MOFs. , However, the reverse of this process, resolvation, has received little, if any, attention. From a practical standpoint, it is important to understand the limits of these materials in liquid-phase applications.…”

A Zeolite‐confined Pd/Acid Sites for High Efficiency of B−H Cleavage

“…The hydrolytic dehydrogenation of boron‐based compounds with high hydrogen content, low molecular weight and good solubility is considered as an attractive way to generate hydrogen (H 2 ) for energy demand [1,2] . Pd nanometal has been reported to be one of the most efficient catalyst for this H 2 revolution reactions, but the maximum utilization of active sites and high stability of nanoparticles is still needed for the practical application [3,4] .…”