title: Highly Efficient Catalytic Hydrogen Evolution from Ammonia Borane Using the Synergistic Effect of Crystallinity and Size of Noble-Metal-Free Nanoparticles Supported by Porous Metal-Organic Frameworks.
abstract: A series of nonprecious metal nanoparticles (NPs) supported by metal-organic framework MIL-101 were synthesized using four methods and their catalytic performance on hydrogen evolution from ammonia borane (NH3BH3) was studied. The results showed that the crystalline Co NPs with size of 4.5-8.5 and 14.5-24.5 nm had low activities featuring the total turnover frequency (TOF) values of 9.9 and 4.5 molH2molcat-1min-1, respectively. In contrast, the amorphous Co NPs with size of 1.6-2.6 and 13.5-24.5 nm exhibited high activities featuring the total TOF values of 51.4 and 22.3 molH2molcat-1min-1, respectively. The remarkably different activities could be ascribed to the different crystallinity and size of Co NPs in the catalysts. Moreover, the ultrasound-assisted in situ method was also successfully applied to bimetallic systems, and MIL-101-supported amorphous CuCo, FeCo and NiCo NPs had the catalytic activities with total TOF values of 51.7, 50.8, and 44.3 molH2molcat-1min-1, respectively, which were the highest in the values of the reported non-noble metal Co-based catalysts. The present approach, namely, using the synergistic effect of crystallinity and size of metal NPs, may offer a new prospect for high-performance and low-cost nanocatalysts.
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Penglong
authors.initials: P
authors.lastname: Liu
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Xiaojun
authors.identifier: http://orcid.org/0000-0002-3877-4373
authors.initials: X
authors.lastname: Gu
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Kang
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Inner Mongolia Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University , Hohhot 010021, Inner Mongolia, China.
authors.forename: Haiquan
authors.identifier: http://orcid.org/0000-0003-2164-3219
authors.initials: H
authors.lastname: Su
keywords: catalyst; hydrogen evolution; metal nanoparticle; metal−organic framework; synergistic effect