THE SYNTHESES OF POLYQUINOLINES WITH 2,2'-PYRIDYLQUINOLINE AND 2,6-DIQUINOLYLPYRIDINE AS LIGAND AND THEIR APPLICATIONS IN SOME CATALYTIC REACTIONS

The polyquinolines with 2,2'-pyridylquinoline as bidentate and 2,6-diquinolylpyridine as tridentate ligand have been prepared from 4,4-dlamino- 3,3'-dibenzoyldiphenyl ether, 4,4'-diacetyldiphenyl ether and 1,4-bis (2-acetylpyridyl-6-oxy) benzene, 2,6-diacetylpyridine, respectively. These polyquinoline-supported ligands have been used in hydrogenation and hydroformylation of olefins with some transition metal complexes.

A novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite oxide with surface doping of Y and its application in Pd-only three-way catalyst

The ceria-zirconia compound oxide-supported noble metal Pd(Pd@CZ)is widely used in three-way catalyst.Moreover,the surface structure of CZ plays an important role in catalytic activity of Pd.However,how to regulate the surface structure of CZ and clarify the structure–activity relationship is still a challenge.In this paper,a strategy is proposed to develop high activity Pd@CZ nanocatalysts by tuning Y doping sites in CZ.The precipitate-deposition method is developed to prepare the novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite with surface doping of Y(CZ-Y-S).In addition,the Pd@CZ-Y-S(Pd supported on CZ-Y-S)exhibits superior catalytic activity for HC,CO,and NO oxide,wherein,for CO and C_(3)H_(6) oxidation,the low-temperature activity of Pd@CZ-Y-S is still 20%higher than that of Pd@CZ-Y-B(Y bulk doping)and commercial Pd@CZ after 1000℃/4 h aging.The effect mechanism is further studied by density functional theory(DFT)calculation.Compared with Pd@CZ-Y-B,Pd@CZ-Y-S shows the lower CO oxide reaction energy barriers due to the weaker adsorption strength of O2.The Y surface doping strategy could provide valuable insights for the development of highly efficient Pd@CZ catalyst with extensive applications.

Atomically Dispersed Catalysts:Precise Synthesis,Structural Regulation,and Structure-Activity Relationship

Atomically dispersed catalysts(ADCs)have been diffusely researched for the development of advanced catalytic processes owing to their welldefined structure,high atomic utilization,and outstanding activity.Precisely decoding the intrinsic structures and coordination microenvironments of ADCs still confronts significant challenges.Overcoming these challenges is important for profound understanding of the structure-activity relationships and directing the future design of ADCs.Herein,this minireview summarizes recent progress and advanced characterization techniques for the engineering of ADCs,including single-atom catalysts,dualatom catalysts,and atomic cluster catalysts with regard to precise synthesis,structural regulation,and the structure-performance relationship.The catalytic merits and regulation strategies of recent breakthroughs in energy conversion,enzyme mimicry,and organic synthesis are thoroughly discussed to disclose the catalytic mechanism-guided ADCs design.Finally,a comprehensive summary of the future challenges and potential prospects is presented to stimulate more design and application possibilities for ADCs.We believe that this comprehensive minireview will open up novel pathways for the widespread utilization of ADCs in diverse catalytic processes.

TiO_(2)-supported Single-atom Catalysts:Synthesis,Structure,and Application

In recent years,single-atom catalysts(SACs)have attracted increasing attention in catalysis.However,their stability is considerably challenging.As a result,fine-tuning the interaction of metal single atoms(SA)with different types of supports has emerged as an effective strategy for improving their thermal and chemical stabilities.Owing to its non-toxicity,cost-effectiveness,high abundance,and excellent stability,as well as presence of rich,tunable,and reliable anchor sites for metal SA,TiO_(2)has been extensively explored as a superior support for SACs.In this review,recent advances of TiO_(2)-supported SACs(M1/TiO_(2))are discussed,and synthetic strategies,structure elucidation,and catalytic applications are summarized.First,the recently developed synthetic strategies for M1/TiO_(2)arehighlighted and summarized,identifying the major challenges for the precise fabrication of M1/TiO_(2).Subsequently,key characterization techniques for the structure identification of M1/TiO_(2)are discussed.Next,catalytic applications of M1/TiO_(2)are highlighted,viz.photocatalysis,electrocatalysis,and thermocatalysis.In addition,the mechanism via geometric structures and electronic states of metal centers facilitate catalytic reactions is outlined.Finally,opportunities and challenges of M1/TiO_(2)in catalysis are discussed,which may inspire the future development of M1/TiO_(2)for multifunctional catalytic applications.

Mechanistic understanding of Cu-based bimetallic catalysts

Copper has received extensive attention in the field of catalysis due to its rich natural reserves,low cost,and superior catalytic performance.Herein,we reviewed two modification mechanisms of co-catalyst on the coordination environment change of Cu-based catalysts:(1)change the electronic orbitals and geometric structure of Cu without any catalytic functions;(2)act as an additional active site with a certain catalytic function,as well as their catalytic mechanism in major reactions,including the hydrogenation to alcohols,dehydrogenation of alcohols,water gas shift reaction,reduction of nitrogenous compounds,electrocatalysis and others.The influencing mechanisms of different types of auxiliary metals on the structure-activity relationship of Cu-based catalysts in these reactions were especially summarized and discussed.The mechanistic understanding can provide significant guidance for the design and controllable synthesis of novel Cu-based catalysts used in many industrial reactions.

Co_(78)Si_(8)B_(14)metallic glass:A highly efficient and ultra-sustainable Fenton-like catalyst in degrading wastewater under universal pH conditions

Overcoming the pH limitation and increasing the catalyst reusability remain pressing demands for metal-lic glass(MG)in wastewater remediation.Herein,Co_(78)Si_(8)B_(14)MG ribbons are used to degrade dye wastew-ater by activating hydrogen peroxide(H_(2)O_(2))as Fenton-like catalysts.The Co-based MG catalysts exhibit high degradation efficiency under both acidic and alkaline conditions,and the kinetic reaction rate at pH 10(0.176 min^(−1)) and pH 4(0.089 min^(−1)) is 5.9 and 1.2 times higher than that of the extensively studied Fe-based MG catalysts,respectively.Impressively,the Co-based MG catalysts can be reused up to 20-60 times at universal pH conditions,demonstrating fairly good reusability.The newly discovered Co-based MG catalysts do not follow the classical Fenton reactions with H_(2)O^(2) the way Fe-based MGs do.In an acid environment,hydroxyl radicals play a dominant role in the degradation,while in an alkaline environ-ment,the effect of hydroxyl radicals is weakened,and Co^(3+) ions exert a relatively major function on the degradation.The excellent performance in catalytic activity and reusability at universal pH conditions of the Co-based MGs will inspire the development of MGs in wastewater treatment.

Direct synthesis of large-area Al-doped graphene by chemical vapor deposition:Advancing the substitutionally doped graphene family

Graphene doping continues to gather momentum because it enables graphene properties to be tuned,thereby affording new properties to,improve the performance of,and expand the application potential of graphene.Graphene can be chemically doped using various methods such as surface functionalization,hybrid composites(e.g.,nanoparticle decoration),and substitution doping,wherein C atoms are replaced by foreign ones in the graphene lattice.Theoretical works have predicted that graphene could be substitutionally doped by aluminum(Al)atoms,which could hold promise for exciting applications,including hydrogen storage and evolution,and supercapacitors.Other theoretical predictions suggest that Al substitutionally doped graphene(AIG)could serve as a material for gas sensors and the catalytic decomposition of undesirable materials.However,fabricating Al substitutionally doped graphene has proven challenging until now.Herein,we demonstrate how controlled-flow chemical vapor deposition(CVD)implementing a simple solid precursor can yield high-quality and large-area monolayer AIG,and this synthesis is unequivocally confirmed using various characterization methods including local electron energy-loss spectroscopy(EELS).Detailed high-resolution transmission electron microscopy(HRTEM)shows numerous bonding configurations between the Al atoms and the graphene lattice,some of which are not theoretically predicted.Furthermore,the produced AIG shows a CO_(2) capturability superior to those of other substitutionally doped graphenes.