Hello,
A yearly allocation for the LCRC cluster has been requested with the
following updated information:
Submitter/PI: Cong Liu
Project Name: Bio_catalysis
Division: MSD
Project title: Biomass Catalysis for Energy
Associated funding: Director's Fellowship at Argonne
Other Systems:
Science: A critical challenge for biomass conversion to fuels is to develop efficient multi-functional catalysts that facilitate the complex multi-step processes. The necessary chemical conversions in biomass catalysis often include ring opening (e.g., C-O bond breaking), dehydroxygenation/hydrogenation, and coupling reactions, etc. It is known that most of the metal-containing catalysts are only able to catalyze one specific conversion step effectively, while possibly failing on other steps. This is due to the different reaction mechanisms involved in different chemical conversions. For instance, our previous studies of CO2 activation by 3d transition metal complexes have shown that C-O bond cleavage occurs more easily with earlier metal catalysts while hydrogenation reaction favors with later metal systems. On the other hand, current multi-functional catalysts show lack of efficiency and often require high temperature and pressure. Better understanding the reaction mechani
sms of biomass conversions using computational tools is essentially crucial to new catalysts development. Our group has considerable experience in the area of computational modeling of catalytic pathways as well as molecular simulations on accurately predicting thermochemical properties of chemical conversions of sugar molecules. These studies show, among other findings, that reaction mechanisms of biomass catalysis can provide valuable insights and guidance for experimental discovery of novel catalysts.
Our work in this area will be using first principle-based calculations to develop better understandings of the possible reaction pathways for converting anhydrosugars and furans to diesel fuels. Anhydrosugars and furans are major primary products from biomass pyrolysis. These C5 or C6 compounds are potential source to synthesize diesel fuels that are a mixture of C8-C21 hydrocarbon compounds. In order to convert the C5 or C6 chemicals into diesel fuels, an important step is to activate a C=C bond to carry out C-C coupling reaction. On the other hand, ring opening and hydrogenation will be used to either saturate a C=C bond or to remove the oxygens. Recently, nano-scale materials have received increased attention on biomass catalysis, because of the ability of these materials to activation inert chemical bonds. For instance, Atesin et al has reported a selective etheric C-O bond hydrogenolysis catalyzed by Ln(Otf)3/Pd-nanoparticles in ionic liquid. Therefore, designing appropr
iate nano-scale heterogeneous catalysts that can facilitate C-C coupling reaction, and multi-functional catalysts for both ring-opening and hydrogenation, is a key scientific challenge that we are going to address in this project.
Quantum mechanical calculations will be carried out as follows:
a. Identifying suitable computational methods
The overall reactions involved in the investigations will be identified and the thermodynamic data for these reactions will be analyzed with a series of candidate computational methods, including both DFT and higher level ab initio methods. Based on our experience, B3LYP (DFT) will be utilized to carry out geometry optimizations and frequency calculations. The energy calculations will be performed with also G4MP2, CCSD(T) and MP2 methods. The highly accurate G4MP2 method that was developed by our group will be used as the bench mark method. The reaction energy and barrier will be calculated for these overall reactions. The most suitable method will be chosen based on efficient computational time and acceptable accuracy.
b. Reaction pathways
The themochemistry of individual reactions with detailed reaction pathways including important intermediates and transition states is the essential first step towards the understanding of the chemical transformations. This will be investigated using the suitable computational method from step a. Since the chemical transformations such as C-C coupling reactions are rather complicated and will generate many possible intermediate and product species, detailed reaction pathways and all the possible species will be calculated. In addition to gas phase calculations, non-aqueous solvent effect will be considered for reaction energies and barriers.
c. The catalysis of C-C coupling reactions
The C-C coupling reaction is the key step to convert C5-C6 compounds from the biomass pyrolysis to C8-C21 diesel fuel compounds. Diels-Alder (DA) reactions and aldol condensation are available reactions to achieve this type of transformations. Both homogeneous and heterogeneous catalysts will be studied, in which transition metal complexes (will be used for homogeneous catalysis and metal/metal oxide/alloy nanoparticles will be used for heterogeneous catalysis. For the homogeneous catalysis of the DA reaction, for instance, Lewis acid metal complexes will be considered as potential molecular catalysts. The catalytic properties of Lewis acid metal for DA reaction are due to the coordination of the metal to the functional groups of 1,3-diene, causing the decrease of the LUMO energy of the diene. Thus in the studies of the homogeneous catalysts the effect of the metal center will be the focus of interest. Examples of potential catalysts include 3d metal complexes such as titaniu
m dichloride diisopropoxide (Ti(IV)Cl2(iPrO)2), Cr(III), Ni(II) and Cu(II) pincer complexes, and Pd (II)(acac)2 complex. These fundamental studies of molecular models will provide constructive guidance for choosing heterogeneous catalysts, and a set of nanoparticle catalysts will be selected for further investigations, and examples include BaTiO3, Pd and Cu nanoparticles. The correlations and differences between the homogeneous and heterogeneous catalysis will be analyzed, in terms of the catalytic properties of the metal, the impact of the ligands, and the steric/structural effects.
d. Multi-functional catalysts for ring opening and hydrogenation reaction
An important step of getting the diesel fuel products is to remove the unsaturated bonds and oxygens in the longer chain carbon compounds. In many cases, this step involves both ring opening (breaking C-O bond in a ring) and hydrogenation (removing oxygens). To facilitate both reactions, efficient multi-function catalysts need to be developed. An ideal catalyst would be a bimetallic nanoparticle catalyst supported on a high surface area material, in which one metal acts as an oxophilic acid to reduce the polar bond and the other metal is being a base to help produce dissociated hydrogen. Potential catalysts include Au/Fe3O4 and Au/ZnO nanoparticles, as well as Pt or Pd metal nanoparticles-zeolite catalysts. The catalytic properties will be measured by reaction energetic.
Project description: Quantum mechanical calculations will be carried out as follows:
a. Identifying suitable computational methods
The overall reactions involved in the investigations will be identified and the thermodynamic data for these reactions will be analyzed with a series of candidate computational methods, including both DFT and higher level ab initio methods. Based on our experience, B3LYP (DFT) will be utilized to carry out geometry optimizations and frequency calculations. The energy calculations will be performed with also G4MP2, CCSD(T) and MP2 methods. The highly accurate G4MP2 method that was developed by our group will be used as the bench mark method. The reaction energy and barrier will be calculated for these overall reactions. The most suitable method will be chosen based on efficient computational time and acceptable accuracy.
b. Reaction pathways
The themochemistry of individual reactions with detailed reaction pathways including important intermediates and transition states is the essential first step towards the understanding of the chemical transformations. This will be investigated using the suitable computational method from step a. Since the chemical transformations such as C-C coupling reactions are rather complicated and will generate many possible intermediate and product species, detailed reaction pathways and all the possible species will be calculated. In addition to gas phase calculations, non-aqueous solvent effect will be considered for reaction energies and barriers.
c. The catalysis of C-C coupling reactions
The C-C coupling reaction is the key step to convert C5-C6 compounds from the biomass pyrolysis to C8-C21 diesel fuel compounds. Diels-Alder (DA) reactions and aldol condensation are available reactions to achieve this type of transformations. Both homogeneous and heterogeneous catalysts will be studied, in which transition metal complexes (will be used for homogeneous catalysis and metal/metal oxide/alloy nanoparticles will be used for heterogeneous catalysis. For the homogeneous catalysis of the DA reaction, for instance, Lewis acid metal complexes will be considered as potential molecular catalysts. The catalytic properties of Lewis acid metal for DA reaction are due to the coordination of the metal to the functional groups of 1,3-diene, causing the decrease of the LUMO energy of the diene.12 Thus in the studies of the homogeneous catalysts the effect of the metal center will be the focus of interest. Examples of potential catalysts include 3d metal complexes such as titan
ium dichloride diisopropoxide (Ti(IV)Cl2(iPrO)2), Cr(III), Ni(II) and Cu(II) pincer complexes, and Pd (II)(acac)2 complex. These fundamental studies of molecular models will provide constructive guidance for choosing heterogeneous catalysts, and a set of nanoparticle catalysts will be selected for further investigations, and examples include BaTiO3, Pd and Cu nanoparticles. The correlations and differences between the homogeneous and heterogeneous catalysis will be analyzed, in terms of the catalytic properties of the metal, the impact of the ligands, and the steric/structural effects.
d. Multi-functional catalysts for ring opening and hydrogenation reaction
An important step of getting the diesel fuel products is to remove the unsaturated bonds and oxygens in the longer chain carbon compounds. In many cases, this step involves both ring opening (breaking C-O bond in a ring) and hydrogenation (removing oxygens). To facilitate both reactions, efficient multi-function catalysts need to be developed. An ideal catalyst would be a bimetallic nanoparticle catalyst supported on a high surface area material, in which one metal acts as an oxophilic acid to reduce the polar bond and the other metal is being a base to help produce dissociated hydrogen. Potential catalysts include Au/Fe3O4 and Au/ZnO nanoparticles, as well as Pt or Pd metal nanoparticles-zeolite catalysts. The catalytic properties will be measured by reaction energetic.
Industry partnership:
Project URL:
Current FY Hours Used: undetermined amount
New FY Requested allocation: 400000
Q1: 100000
Q2: 100000
Q3: 100000
Q4: 100000
Justification:
Storage requirements:
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