Study On The Controllable Preparation And Catalytic Performance Of Ruthenium-based Nanomaterials

As a noble metal element,Ru element contains many empty orbitals and has excellent catalytic performance.However,due to the small content of Ru in nature,it has been restricted from being developed in large quantities to be used as a catalyst.In addition,compared with other non-noble metal element nano-catalysts,Ru nano-catalysts are less stable and tend to aggregate to reduce their catalytic activity.Therefore,in this paper,Ru is the main element.By introducing other non-noble metal elements,a series of Ru-based multimetal nanocatalysts can be controllable preparation,and their catalytic properties have been studied.The specific research contents of this paper are as follows:1.With Ru(acac)₃,Ni(acac)₂,Cu(acac)₂and Fe(acac)₃ as metal precursors,by adjusting the amount and type of metal precursors and the reaction temperature,a series of hexagonal Ru-Ni-"M"(M=none,Cu and Fe)alloy NPs can be controllable preparation.Then,using the catalytic degradation of p-NP as a model,according to the efficiency of p-NP degradation,the ratio of Ru-Ni,the reaction temperature and the doping type of the third element are gradually optimized.Finally,Ru₄₄Ni₂₈Fe₂₈ alloy NPs are the strongest catalysts that can completely degrade p-NP,and their speeds are 31 times,29 times and 5 times faster than Ni NPs,Ru NPs and Ru₆₀Ni₄₀ NPs,respectively.In addition,Ru₄₄Ni₂₈Fe₂₈alloy NPs are easy to precipitate,which can be separated from the catalytic system many times.After ten consecutive separations,the dispersibility and morphology of Ru₄₄Ni₂₈Fe₂₈ alloy NPs have not changed significantly,and they still maintain good catalytic activity and selectivity in the catalytic reaction.At the same time,Ru₄₄Ni₂₈Fe₂₈ NPs membrane was prepared at the oil-water(ethyl acetate-water)interface.The membrane is transferred to different solid macro substrates(eg glass,silicon wafers)by evaporating ethyl acetate.The resulting tightly packed Ru₄₄Ni₂₈Fe₂₈NPs membrane is a good Raman substrate.The catalytic performance of Ru₄₄Ni₂₈Fe₂₈NPs membrane was measured by using 4-NTP as a catalytic substrate and Raman probe.In the presence of Na BH₄,the membrane can catalyze the complete conversion of 4-NTP to 4-ATP.2.Using Ru(acac)₃ and Cu(acac)₂ as metal precursors,Ru-Cu alloy nanocatalysts with different structures were synthesized by one-step method.The catalytic performance of Ru-Cu alloy nano-catalyst was measured by catalytic reduction of chromium(Cr⁶⁺)as a template.Compared with Ru NPs and Ru-Cu NCs,Ru-Cu solid NPs have better catalytic performance,because the geometry and internal electronic properties of NPs will change due to changes in doping elements or reaction conditions.In the process of catalytic reduction of Cr⁶⁺,Ru₂Cu₂(5 h,p H 8)NPs had excellent catalytic performance.In addition,Ru₂Cu₂(5 h,p H 8)NPs had excellent stability.After repeated testing,the dispersibility was still good,and the morphology had not changed significantly.3.Taking Ru(acac)₃,Co(acac)₃,Zn(acac)₂,Cu(acac)₂ and Fe(acac)₃ as metal precursors,by adjusting the types of metal precursors and synthetic system p H value,controllable synthesis of a series of Ru-based two-element alloy NPs.Then,using the catalytic degradation of Cr⁶⁺as a template,the catalytic performance of alloy NPs was measured.Within a few tens of minutes,these alloy NPs have significant catalytic degradation performance for Cr⁶⁺.According to the time required for the catalytic degradation of Cr⁶⁺and the efficiency of degradation,the types of doped elements and the p H value of the synthesized NPs environment system were gradually optimized.Finally,the minimum time required for Ru₂Co₂ alloy NPs to catalyze the complete degradation of Cr⁶⁺.In addition,after many cycles,the dispersion of Ru₂Co₂ alloy NPs is good,and its morphology has not changed significantly,and it still has good catalytic activity in the catalytic degradation of Cr⁶⁺.