The rational design and construction of high-performance heterogeneous non-noble metal catalysts is an urgent need for the practical application of selective hydrogenation of quinoline and its derivatives. In this work, N-doped porous carbons encapsulated highly-dispersed Cu nanoparticles catalyst (Cu@NC-900) was synthesized by pyrolysis of Cu-MOF precursor, based on the design concept of high efficiency, low cost and excellent durability. Interestingly, the Cu@NC-900 catalyst exhibits extremely high activity, chemo-selectivity and recoverability for the hydrogenation of quinoline and its derivatives using ammonia borane as the hydrogen resources under mild conditions. The characterization results of PXRD, SEM, TEM, Raman spectrum, XPS, EDS and density functional theory (DFT) calculations revealed that the doped N and highly-dispersed Cu species in the catalyst can change the electronic density of the catalyst surface, and thus improve the hydrogenation catalytic performance. This study provides a new idea for rational design of high-performance non-noble metal catalysts for hydrogenation of quinolines under mild conditions.

During the catalytic process, the microenvironment and surface area of the catalyst will affect the catalytic performance. Hence, an assisted organic linker coated metal-organic framework (MOF) has been applied, to form Ni/HNC (HNC represents hollow nanocage) for electrocatalytic CO₂ reduction. Remarkably, Ni/HNC achieves superb activity with high Faradaic efficiency (FE) of 97.2% at 0.7 V vs. reversible hydrogen electrode (RHE) towards CO₂ conversion to CO. In contrast to Ni/NPC (afforded from the naked MOF), the Ni/HNC displays higher FE and selectivity on CO rather than H₂, owing to the large nanocage which extraordinarily facilitates CO₂ enrichment and the active sites easily accessible. This work provides a general and feasible route to construct high-efficient electrochemical CO₂ reduction reaction (EC-CO₂RR) catalysts via post-modified MOFs.