Highly Efficient Iridium–Iron–Molybdenum Catalysts Condensed on Boron Nitride for Biomass-Derived Diols’ Hydrogenolysis to Secondary Monoalcohols

Abstract

A trade-off of activity−selectivity exists in primary C−O hydrogenolysis of biomass-derived diols to secondary alcohols over bimetallic catalysts, especially the combination of noble metal and early transition metal in the metallic state and metal oxide state, respectively. Herein, the combination of high surface concentration of boron nitride (BN)-supported metals and the addition of Mo as third metal broke the trade-off. High yields (>50%) of secondary alcohols were obtained with robust productivity up to 25-fold based on Ir over Ir−Fe 0.13 −Mo 0.08 /BN (Ir = 20 wt %, Fe/Ir = 0.13, Mo/Ir = 0.08) than previously reported Ir−Fe catalysts. In contrast, simply increasing the loading amount of Ir−Fe catalysts or the addition of Mo species only enhanced the productivity by <2−4-fold. Various characterizations showed that large Ir loading enables the formation of condensed nanostructures (∼2 nm) on the BN support, which further alloy with Mo and Fe to form an face centred cubic (fcc)-type trimetallic alloy with surface enrichment of Fe. On the other hand, in Ir− Fe 0.25 −Mo 0.08 /BN with lower Ir (5 wt %) and lower Ir-based activity, the Mo species were rather bound on the support surface possibly as the MoB x state. These structures were formed by simple impregnation and reduction with H 2 at the reaction temperature (453 K). The high activity of Ir−Fe 0.13 −Mo 0.08 /BN (20 wt % Ir) is derived from two aspects: (1) the formation of condensed nanostructures (∼2 nm) exposing more active sites and (2) alloying with Mo to modify the electronic state of Ir to enhance the H 2 activation ability, as shown by the decreased E a (82−84 → 67 kJ mol −1 ).

Studies of Anticancer Activities In Vitro and In Vivo for Butyltin(IV)–Iridium(III) Imidazole–Phenanthroline Complexes with Aggregation-Induced Emission Properties

“…Cancer remains a devastating disease, and continuous research and improvement of treatment strategies are urgently necessary. − Metallic anticancer drugs have attracted extensive attention in the biological field, including biocatalysis, biological probes, and biopharmaceuticals. − Among these, platinum-based drugs have been widely employed in the treatment of cancer, however, toxic side effects and drug resistance have prompted the exploration for alternatives with different anticancer mechanisms. , Recently, iridium­(III) (Ir III ) complexes have drawn wide concern because of their unique chemical properties and their distinct anticancer mechanisms in comparison to platinum-based drugs. − Ye et al designed and synthesized mitochondria-targeting coumarin-derived cyclometalated Ir III complexes, possessing rich photophysical properties and higher antiproliferative activity against various cancer cells, including cisplatin-resistant cancer cells . Guan et al obtained two phenylbenzoxazole-modified Ir III complexes (NecroIr1 and NecroIr2) as necroptosis inducers in cisplatin-resistant lung cancer (A549/DDP) cells.…”