Journal of the American Chemical Society, Dec 7, 2021
Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not... more Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not been recognized as a catalyst for acid transformation of active sites on solid surface. Here, we report the H2-promoted hydration of alkenes (such as styrenes and cyclic alkenes) and epoxy alkanes over single atom Co dispersed nitrogen-doped carbon (Co-NC) via a transformation mechanism of acid-base sites. Specifically, the specific catalytic activity and selectivity of Co-NC are more superior to those of classical solid acids (acidic zeolites and resins) per μmol of acid, whereas the hydration catalysis does not take place in a nitrogen atmosphere. Detailed investigations indicate that H2 can be heterolyzed on the CoN to form H -CoN -H + and then converted into OH -CoN -H + accompanied by H2 generation via a H2O-mediated path, which significantly reduces the activation energy for hydration reactions. This work not only provides a novel catalytic method for hydration reactions but also removes the conceptual barriers between hydrogenation and acid catalysis.
The hydrogen-bond strengthen the *COOH adsorption and lower the CO2(g)→*COOH energy barrier on Cu... more The hydrogen-bond strengthen the *COOH adsorption and lower the CO2(g)→*COOH energy barrier on Cu–N–C electrocatalyst, simultaneously yielding a high CO FE and TOF.
Abstract Electrocatalytic Nitrogen Reduction Reaction (ECNRR) is a promising alternative NH3 prod... more Abstract Electrocatalytic Nitrogen Reduction Reaction (ECNRR) is a promising alternative NH3 production method relative to Haber-Bosch process. However, the ECNRR still suffers from rather low NH3 yield and selectivity (Faradaic efficiency (FE)) due to the poor catalytic activity of catalysts. Herein, benefiting from interface engineering, FeNi2S4/NiS hetero-interface electrocatalysts with unique electronic structures are successfully constructed, which the optimized catalyst can enhance the adsorption of N2 molecules meanwhile inhibit H atoms adsorption. Significantly, the NH3 yield and FE of FNS/CC-2 are reached to 128.398±1.32 μg h−1 cm−2 and 28.64 ± 0.18% which are higher than most of non-noble metal-based NRR electrocatalysts in alkaline electrolyte reported. Detailed experimental investigation and DFT calculations reveal that the enhanced electrocatalytic performance and selectivity of FeNi2S4/NiS towards N2 are attributed to the changes of the D-band center and electronic structure of electrocatalyst surface. The construction strategy of this NRR electrocatalyst provides a new avenue on electrocatalytic research.
Herein, novel green synthetic routes to 4-hydroxy-2-cyclopentenone (HCP) and 2-cyclopentenone (CP... more Herein, novel green synthetic routes to 4-hydroxy-2-cyclopentenone (HCP) and 2-cyclopentenone (CPE) from biomass-derived furfuryl alcohol via double-metal cyanide catalysis are proposed.
Recently, layered double hydroxides (LDHs) have attracted intensive research interest as the next... more Recently, layered double hydroxides (LDHs) have attracted intensive research interest as the next-generation supercapacitor electrodes due to their unique two-dimensional (2D) hydrotalcite-like structure. However, the inevitable agglomeration significantly decreases the accessible surface areas and blocks the pseudocapacitive sites, thus severely hinders their electrochemical applications. Herein, we develop a facile one-step growth approach to fabricate porous agglomerate of NiCo-LDH nanosheets and reduced graphene oxide (rGO) nanoflakes. By adjusting feeding molar ratios, the obtained NiCo-LDH/rGO electrode delivers a high specific capacity of 879.5 C/g at a current density of 0.5 A/g and still remains 485 C/g at 20 A/g. Furthermore, the fabricated asymmetric supercapacitor (ASC) has demonstrated a superior energy density of 48.7 W h/kg at a power density of 401 W/kg. After 2000 cycles, the assembled ASC exhibits an improved capacity retention of 81% within a potential window of 1.6 V at 2 A/g.
The composites consisting of nitrogen-doped carbon nanotubes (N-CNTs) and nitrogen-doped carbon n... more The composites consisting of nitrogen-doped carbon nanotubes (N-CNTs) and nitrogen-doped carbon nanofibers (N-CNFs) were fabricated using a mixture of nickel foam (template) and imidazole (solid precursor) in a facile one-step chemical vapor deposition (CVD) process. The morphology and microstructure of the Ndoped carbon nanotubes/N-doped carbon nanofibers hierarchical composites (N-CNTs/N-CNFs) were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, and X-ray photoelectron spectroscopy. The results indicated that the sample manifests regular hierarchical composites, great graphitization, and nitrogen doping. Furthermore, a probable growth mechanism is presented to analyze the composites.
The simultaneous conversion of C5 and C6 mixed sugars into methyl levulinate (MLE) has emerged as... more The simultaneous conversion of C5 and C6 mixed sugars into methyl levulinate (MLE) has emerged as a versatile strategy to eliminate costly separation steps. However, the traditional upgrading of C5 sugars into MLE is very complex as it requires both acid‐catalyzed and hydrogenation processes. This study concerns the development of a one‐pot, hydrogenation‐free conversion of C5 sugars into MLE over different acid catalysts at near‐critical methanol conditions with the help of 1,3,5‐trioxane. For the conversion of C5 sugars over zeolites without the addition of 1,3,5‐trioxane, the MLE yield is quite low, owing to low hydrogenation activity. The addition of 1,3,5‐trioxane significantly boosts the MLE yield by providing an alternative conversion pathway that does not include the hydrogenation step. A direct comparison of the catalytic performance of five different zeolites reveals that Hβ zeolite, which has high densities of both Lewis and Brønsted acid sites, affords the highest MLE yi...
High-throughput technology has generated large-scale protein interaction data, which is crucial i... more High-throughput technology has generated large-scale protein interaction data, which is crucial in our understanding of biological organisms. Many complex identification algorithms have been developed to determine protein complexes. However, these methods are only suitable for dense protein interaction networks, because their capabilities decrease rapidly when applied to sparse protein-protein interaction (PPI) networks. In this study, based on penalized matrix decomposition (PMD), a novel method of penalized matrix decomposition for the identification of protein complexes (i.e., PMD pc) was developed to detect protein complexes in the human protein interaction network. This method mainly consists of three steps. First, the adjacent matrix of the protein interaction network is normalized. Second, the normalized matrix is decomposed into three factor matrices. The PMD pc method can detect protein complexes in sparse PPI networks by imposing appropriate constraints on factor matrices. Finally, the results of our method are compared with those of other methods in human PPI network. Experimental results show that our method can not only outperform classical algorithms, such as CFinder, ClusterONE, RRW, HC-PIN, and PCE-FR, but can also achieve an ideal overall performance in terms of a composite score consisting of F-measure, accuracy (ACC), and the maximum matching ratio (MMR).
A surrogate of jet fuel range hydrocarbons was produced from renewable feedstock such as Camelina... more A surrogate of jet fuel range hydrocarbons was produced from renewable feedstock such as Camelina oil, palm oil and the fatty acid methyl esters (FAME’s) derived from these oils. The process includes two steps involving hydrocracking and reforming in presence of the catalyst. This work involves the different reaction conditions by taking temperature, pressure, time of reaction and amount of catalyst as variable parameters. In this work bi-functional catalysts NiMo and CoMo supported on g-alumina were used along with an industrial catalyst. For this work bi-functional catalysts are prepared and used in the production of jet fuel. The feedstock, intermediate product and final product were analyzed by using ATR-FTIR, SEM-EDS, TGA and GC-MS. For analyzing the catalyst properties XRD, SEM-EDS and ASAP were used
Synthesis of Zeolite Y From an Energy Conserving Route Using Seed Directed Crystallization. The n... more Synthesis of Zeolite Y From an Energy Conserving Route Using Seed Directed Crystallization. The need for renewable energy is of great importance as the supply of petroleum based fuels dwindle. Due to their porous structure and Brönsted acidity, zeolite Y is an excellent candidate for the conversion of fatty acid methyl esters produced from algal biomass to more energy dense hydrocarbons. We will report on a seed directed synthesis technique for the crystallization of zeolite-Y without the use of organic templates. This synthesis is controlled by the composition of the solution, followed by growth of the zeolite seeds to larger sizes by incorporation of precursors from the solution. The exclusion of organic templates allows for the elimination of the calcination step to remove organics from the framework of the material. Compared to the more traditional synthesis route involving organotemplates, seed directed synthesis via hydrothermal treatment at 200oC is a less energy intensive pr...
Various forms of sol-gel activated alumina (AA) have been synthetized and tested as potential ars... more Various forms of sol-gel activated alumina (AA) have been synthetized and tested as potential arsenic adsorbent materials. Some of them included xerogel, aerogel and Nanogel AA. Synthesis of the sol-gel was made following the Yoldas method which included hydrolysis, peptization, gelation and calcination. In the present study, modifications to the Yoldas method to produce aerogel and Nanogel AA included using supercritical-CO2 extraction and addition of nanoparticles, respectively. Equilibrium experiments were conducted to determine optimum pH conditions for adsorption and maximum adsorption capacity. Results were compared with two commercial activated alumina adsorbent materials, namely H-156 and Axens. It has been observed that Xerogel removed arsenic at any pH within the range of 2.0 and 10.0. It has also been observed that the tendency to increase arsenic uptake for the synthesized adsorbents increased in the order or Xerogel AA > Axens > Aerogel AA > H-156 AA > Nanog...
Extraction of biocrude from algal biomass was demonstrated with algal biomass containing more tha... more Extraction of biocrude from algal biomass was demonstrated with algal biomass containing more than 90% of water in biomass. This method offers potential solution for extraction of oil in less energy intensive way compared to other extraction methods. Conventional solvent extraction methods folch and Bligh & dyer are also performed and compared to subcritical water extraction in terms of extraction efficiency and energy expenses. With the help of design of experiments (DOE) effects of reaction parameters biomass loading, temperature and extraction time on extraction are studied and optimized. The purification of biocrude to produce clear algal oil was also performed through activated charcoal bed. The fatty acid composition of algal biomass and extracted biocrude are analyzed with GC-MS and FT-ICR. Thermogravimetric analysis (TGA) is performed to analyze the thermal behavior of biomass. TEM and SEM-EDS instruments have been used to determine the biomass topology and qualitative analy...
Journal of the American Chemical Society, Dec 7, 2021
Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not... more Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not been recognized as a catalyst for acid transformation of active sites on solid surface. Here, we report the H2-promoted hydration of alkenes (such as styrenes and cyclic alkenes) and epoxy alkanes over single atom Co dispersed nitrogen-doped carbon (Co-NC) via a transformation mechanism of acid-base sites. Specifically, the specific catalytic activity and selectivity of Co-NC are more superior to those of classical solid acids (acidic zeolites and resins) per μmol of acid, whereas the hydration catalysis does not take place in a nitrogen atmosphere. Detailed investigations indicate that H2 can be heterolyzed on the CoN to form H -CoN -H + and then converted into OH -CoN -H + accompanied by H2 generation via a H2O-mediated path, which significantly reduces the activation energy for hydration reactions. This work not only provides a novel catalytic method for hydration reactions but also removes the conceptual barriers between hydrogenation and acid catalysis.
The hydrogen-bond strengthen the *COOH adsorption and lower the CO2(g)→*COOH energy barrier on Cu... more The hydrogen-bond strengthen the *COOH adsorption and lower the CO2(g)→*COOH energy barrier on Cu–N–C electrocatalyst, simultaneously yielding a high CO FE and TOF.
Abstract Electrocatalytic Nitrogen Reduction Reaction (ECNRR) is a promising alternative NH3 prod... more Abstract Electrocatalytic Nitrogen Reduction Reaction (ECNRR) is a promising alternative NH3 production method relative to Haber-Bosch process. However, the ECNRR still suffers from rather low NH3 yield and selectivity (Faradaic efficiency (FE)) due to the poor catalytic activity of catalysts. Herein, benefiting from interface engineering, FeNi2S4/NiS hetero-interface electrocatalysts with unique electronic structures are successfully constructed, which the optimized catalyst can enhance the adsorption of N2 molecules meanwhile inhibit H atoms adsorption. Significantly, the NH3 yield and FE of FNS/CC-2 are reached to 128.398±1.32 μg h−1 cm−2 and 28.64 ± 0.18% which are higher than most of non-noble metal-based NRR electrocatalysts in alkaline electrolyte reported. Detailed experimental investigation and DFT calculations reveal that the enhanced electrocatalytic performance and selectivity of FeNi2S4/NiS towards N2 are attributed to the changes of the D-band center and electronic structure of electrocatalyst surface. The construction strategy of this NRR electrocatalyst provides a new avenue on electrocatalytic research.
Herein, novel green synthetic routes to 4-hydroxy-2-cyclopentenone (HCP) and 2-cyclopentenone (CP... more Herein, novel green synthetic routes to 4-hydroxy-2-cyclopentenone (HCP) and 2-cyclopentenone (CPE) from biomass-derived furfuryl alcohol via double-metal cyanide catalysis are proposed.
Recently, layered double hydroxides (LDHs) have attracted intensive research interest as the next... more Recently, layered double hydroxides (LDHs) have attracted intensive research interest as the next-generation supercapacitor electrodes due to their unique two-dimensional (2D) hydrotalcite-like structure. However, the inevitable agglomeration significantly decreases the accessible surface areas and blocks the pseudocapacitive sites, thus severely hinders their electrochemical applications. Herein, we develop a facile one-step growth approach to fabricate porous agglomerate of NiCo-LDH nanosheets and reduced graphene oxide (rGO) nanoflakes. By adjusting feeding molar ratios, the obtained NiCo-LDH/rGO electrode delivers a high specific capacity of 879.5 C/g at a current density of 0.5 A/g and still remains 485 C/g at 20 A/g. Furthermore, the fabricated asymmetric supercapacitor (ASC) has demonstrated a superior energy density of 48.7 W h/kg at a power density of 401 W/kg. After 2000 cycles, the assembled ASC exhibits an improved capacity retention of 81% within a potential window of 1.6 V at 2 A/g.
The composites consisting of nitrogen-doped carbon nanotubes (N-CNTs) and nitrogen-doped carbon n... more The composites consisting of nitrogen-doped carbon nanotubes (N-CNTs) and nitrogen-doped carbon nanofibers (N-CNFs) were fabricated using a mixture of nickel foam (template) and imidazole (solid precursor) in a facile one-step chemical vapor deposition (CVD) process. The morphology and microstructure of the Ndoped carbon nanotubes/N-doped carbon nanofibers hierarchical composites (N-CNTs/N-CNFs) were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, and X-ray photoelectron spectroscopy. The results indicated that the sample manifests regular hierarchical composites, great graphitization, and nitrogen doping. Furthermore, a probable growth mechanism is presented to analyze the composites.
The simultaneous conversion of C5 and C6 mixed sugars into methyl levulinate (MLE) has emerged as... more The simultaneous conversion of C5 and C6 mixed sugars into methyl levulinate (MLE) has emerged as a versatile strategy to eliminate costly separation steps. However, the traditional upgrading of C5 sugars into MLE is very complex as it requires both acid‐catalyzed and hydrogenation processes. This study concerns the development of a one‐pot, hydrogenation‐free conversion of C5 sugars into MLE over different acid catalysts at near‐critical methanol conditions with the help of 1,3,5‐trioxane. For the conversion of C5 sugars over zeolites without the addition of 1,3,5‐trioxane, the MLE yield is quite low, owing to low hydrogenation activity. The addition of 1,3,5‐trioxane significantly boosts the MLE yield by providing an alternative conversion pathway that does not include the hydrogenation step. A direct comparison of the catalytic performance of five different zeolites reveals that Hβ zeolite, which has high densities of both Lewis and Brønsted acid sites, affords the highest MLE yi...
High-throughput technology has generated large-scale protein interaction data, which is crucial i... more High-throughput technology has generated large-scale protein interaction data, which is crucial in our understanding of biological organisms. Many complex identification algorithms have been developed to determine protein complexes. However, these methods are only suitable for dense protein interaction networks, because their capabilities decrease rapidly when applied to sparse protein-protein interaction (PPI) networks. In this study, based on penalized matrix decomposition (PMD), a novel method of penalized matrix decomposition for the identification of protein complexes (i.e., PMD pc) was developed to detect protein complexes in the human protein interaction network. This method mainly consists of three steps. First, the adjacent matrix of the protein interaction network is normalized. Second, the normalized matrix is decomposed into three factor matrices. The PMD pc method can detect protein complexes in sparse PPI networks by imposing appropriate constraints on factor matrices. Finally, the results of our method are compared with those of other methods in human PPI network. Experimental results show that our method can not only outperform classical algorithms, such as CFinder, ClusterONE, RRW, HC-PIN, and PCE-FR, but can also achieve an ideal overall performance in terms of a composite score consisting of F-measure, accuracy (ACC), and the maximum matching ratio (MMR).
A surrogate of jet fuel range hydrocarbons was produced from renewable feedstock such as Camelina... more A surrogate of jet fuel range hydrocarbons was produced from renewable feedstock such as Camelina oil, palm oil and the fatty acid methyl esters (FAME’s) derived from these oils. The process includes two steps involving hydrocracking and reforming in presence of the catalyst. This work involves the different reaction conditions by taking temperature, pressure, time of reaction and amount of catalyst as variable parameters. In this work bi-functional catalysts NiMo and CoMo supported on g-alumina were used along with an industrial catalyst. For this work bi-functional catalysts are prepared and used in the production of jet fuel. The feedstock, intermediate product and final product were analyzed by using ATR-FTIR, SEM-EDS, TGA and GC-MS. For analyzing the catalyst properties XRD, SEM-EDS and ASAP were used
Synthesis of Zeolite Y From an Energy Conserving Route Using Seed Directed Crystallization. The n... more Synthesis of Zeolite Y From an Energy Conserving Route Using Seed Directed Crystallization. The need for renewable energy is of great importance as the supply of petroleum based fuels dwindle. Due to their porous structure and Brönsted acidity, zeolite Y is an excellent candidate for the conversion of fatty acid methyl esters produced from algal biomass to more energy dense hydrocarbons. We will report on a seed directed synthesis technique for the crystallization of zeolite-Y without the use of organic templates. This synthesis is controlled by the composition of the solution, followed by growth of the zeolite seeds to larger sizes by incorporation of precursors from the solution. The exclusion of organic templates allows for the elimination of the calcination step to remove organics from the framework of the material. Compared to the more traditional synthesis route involving organotemplates, seed directed synthesis via hydrothermal treatment at 200oC is a less energy intensive pr...
Various forms of sol-gel activated alumina (AA) have been synthetized and tested as potential ars... more Various forms of sol-gel activated alumina (AA) have been synthetized and tested as potential arsenic adsorbent materials. Some of them included xerogel, aerogel and Nanogel AA. Synthesis of the sol-gel was made following the Yoldas method which included hydrolysis, peptization, gelation and calcination. In the present study, modifications to the Yoldas method to produce aerogel and Nanogel AA included using supercritical-CO2 extraction and addition of nanoparticles, respectively. Equilibrium experiments were conducted to determine optimum pH conditions for adsorption and maximum adsorption capacity. Results were compared with two commercial activated alumina adsorbent materials, namely H-156 and Axens. It has been observed that Xerogel removed arsenic at any pH within the range of 2.0 and 10.0. It has also been observed that the tendency to increase arsenic uptake for the synthesized adsorbents increased in the order or Xerogel AA > Axens > Aerogel AA > H-156 AA > Nanog...
Extraction of biocrude from algal biomass was demonstrated with algal biomass containing more tha... more Extraction of biocrude from algal biomass was demonstrated with algal biomass containing more than 90% of water in biomass. This method offers potential solution for extraction of oil in less energy intensive way compared to other extraction methods. Conventional solvent extraction methods folch and Bligh & dyer are also performed and compared to subcritical water extraction in terms of extraction efficiency and energy expenses. With the help of design of experiments (DOE) effects of reaction parameters biomass loading, temperature and extraction time on extraction are studied and optimized. The purification of biocrude to produce clear algal oil was also performed through activated charcoal bed. The fatty acid composition of algal biomass and extracted biocrude are analyzed with GC-MS and FT-ICR. Thermogravimetric analysis (TGA) is performed to analyze the thermal behavior of biomass. TEM and SEM-EDS instruments have been used to determine the biomass topology and qualitative analy...
Uploads
Papers by Shuguang Deng