Tuning the synthesis of polymetallic-doped ZIF derived materials for efficient hydrogenation of furfural to furfuryl alcohol

Cu, Co and Zn modified N-doped porous carbons (CuCo/Zn@NPC) are prepared using a polymetallic homogeneous doping and self-templating method as high performance non-noble metal catalysts for the hydrogenation of furfural (FF) to furfuryl alcohol (FAL). The CuCo/Zn@NPC-600 catalyst after treatment at 600 °C shows a superior catalytic activity with nearly 100% conversion of FF and an almost 100% selectivity of FAL using H2 at 140 °C. Meanwhile in the catalytic transfer hydrogenation (CTH) using 2-propanol as a H-donor, the conversion of FF reaches 95.8% and the selectivity of FAL is 99.1%. The results show that the Zn dopant leads to 37.3 times higher yield on the CuCo/Zn@NPC-600 catalyst than that on CuCo@NPC-600, and 2.3 times higher than that on Co/Zn@NPC-600 with Cu dopants. The efficient activity of the CuCo/Zn@NPC-600 catalyst is mainly due to the highly dispersed metal nanoparticles, the advanced porous structure resulting from Zn escape from the precursor template, and the synergistic effect between Cu and Co. Furthermore, the CuCo/Zn@NPC-600 catalyst exhibits good recyclability in FF hydrogenation in four cycle tests. The advanced synthesis method using a homogeneous doping and self-templating strategy sheds light on preparing effective catalysts for hydrogenation of biomass-based compounds

Efficient single-atom Ni for catalytic transfer hydrogenation of furfural to furfuryl alcohol

The employment of single-atom catalysts in the catalytic transfer hydrogenation (CTH) of furfural (FF) to furfuryl alcohol (FAL) have never been effectively explored. Herein, Ni single-atoms supported on nitrogen doped carbon (Ni-SAs/NC) catalyst is synthesized and first ever utilized in CTH of FF to FAL. Atomically dispersed Ni-N4 sites change the electron density at the metal center and exhibit specific adsorption and desorption to FF and FAL, promoting an outstanding catalytic performance with turnover frequency (TOF) of 832 h-1 and selectivity as high as 97.1 at 130 oC for 2 h. Such performance is 9-fold higher than that of supported Ni nanocatalysts. The Ni-SAs/NC catalyst also exhibits superior stability for CTH of FF and excellent catalytic activity for other α,β-unsaturated aldehydes. This work provides a new strategy of producing green chemical compounds using catalytic biomass conversion and suggests the future application of long-lasting single-atom catalysts for emerging sustainable technologies

Essential APSES Transcription Factors for Mycotoxin Synthesis, Fungal Development, and Pathogenicity in Aspergillus flavus

Aflatoxins are a potent carcinogenic mycotoxin and has become a research model of fungal secondary metabolism (SM). Via systematically investigating the APSES transcription factors (TFs), two APSES proteins were identified: AfRafA and AfStuA. These play central roles in the synthesis of mycotoxins including aflatoxin and cyclopiazonic acid, and fungal development and are consequently central to the pathogenicity of the aflatoxigenic A. flavus. Loss of AfRafA not only dramatically suppressed aflatoxin cluster expression, subsequently reducing toxin synthesis both in vitro and in vivo, but also impaired conidia and sclerotia development. More importantly, aflatoxin biosynthesis as well as conidia and sclerotia development were fully blocked in ΔAfStuA. In addition, our results supported that AfStuA regulated the aflatoxin synthesis in an AflR-dependent manner. Intriguingly, it was revealed that AfRafA and AfStuA exert an antagonistic role in the regulation of biosynthesis of cyclopiazonic acid. In summary, two global transcriptional regulators for fungal development, mycotoxin production, and seed pathogenicity of the A. flavus system have been established. The two novel regulators of mycotoxins are promising targets for future plant breeding and for the development of fungicides