Chenghua Sun

Controllable fabrication of bulk hierarchical nanoporous palladium by chemical dealloying at various temperature and its thermal coarsening

In the present study, bulk hierarchical nanoporous Pd materials (BHNPP) were successfully prepared. Results show that the microstructure of nanoporous materials can be facile tailored by optimizing the dealloying temperature and the concentration of HCl solutions. The formation mechanisms of BHNPP materials were discussed, which reveal that the nucleation and growth of Pd crystalline is essential to form nanoporous Pd. Surface diffusivities, activation energies and diffusion constants at the bimodal porous structure and the monolithic porous structure of Pd atoms were also evaluated. Furthermore, BHNPP show favorable thermal stability, ligament diameters of which is ~30xa0nm even after heated at 1073xa0K for 1xa0h.

Fabrication and characterization of bulk nanoporous Cu with hierarchical pore structure

In the present study, bulk nanoporous Cu materials with hierarchical porous structure and fine ligaments have been facilely fabricated through chemical dealloying of CuAl alloy that prepared by suction casting. Effect of dealloying temperature on the formation of nanoporous Cu was investigated. Results reveal that robust bulk nanoporous Cu with no noticeable volume shrinkage can be prepared. The Fe adatoms may act as activation barrier for the surface diffusion of Cu adatoms, which is beneficial for the refinement of nanoporous Cu. Moreover, thermal coarsening behavior of nanoporous Cu was also investigated.

Chapter 6:DFT Modelling Tools in CO2 Conversion: Reaction Mechanism Screening and Analysis

The computer-aided molecular modelling of the catalytic conversion of carbon dioxide (CO2) into ‘green’ fuels offers a comprehensive view of the chemical events taking place during the process. This provides crucial information about ‘where’, ‘how’, and ‘why’ and also allows the in silico hypothesising of those promising catalysts before the experimental testing of their catalytic performance. Among the variety of quantum mechanical approaches, well-resolved density functional theory (DFT) has been proven as a fast, robust, and powerful methodology for such purposes. In the present chapter, we review different fundamental aspects of the chemical reactivity with special emphasis on the theoretical point-of-view as well as fully treating the thermodynamics, kinetics, and additional aspects for the DFT modelling of the CO2 conversion mechanism screening through the electrochemical approach.

Characterization and Thermal Stability Properties of Bulk Hierarchical Porous Pd Prepared by Kirkendall Effect and Dealloying Method

We present a facile strategy to synthesize bulk hierarchical porous Pd materials (BHPPd) with pores ranging from a few nanometers to tens of micrometers through chemical dealloying of porous PdAl intermetallics. Owing to the small surface diffusivities of Pd atoms, the pore/ligament size of BHPPd did not coarsen remarkably as the concentration of HCl aqueous solution increases. Thermal stability properties of BHPPd materials at different temperature ranging from 673 to 1073u2009K were evaluated. BHPPd materials show superior thermal stability, whose bicontinuous interpenetrating ligament-channel structure can be maintained even after being annealed at 1073u2009K for 30u2009min. Such properties can be attributed to less defects and less-noble metal residues. Moreover, compression properties of BHPPd materials were also investigated.

Morphology-Controlled Synthesis of Co 3 O 4 Materials and its Electrochemical Catalytic Properties Towards Oxygen Evolution Reaction

AbstractIn the present study, we present a facile strategy to synthesis Co3O4 materials with different morphology. Experimental results show that Co3O4 materials with flower-like, fiber, sheet-like and rod morphologies have been successfully prepared by hydrothermal synthesis in different solvent. The effect of the morphology on the electrochemical catalytic properties were also studied. It is found that sheet-like Co3O4 exhibits the best activity towards oxygen evolution reaction (η10u2009=u2009390xa0mV) in 1xa0M KOH, which can be attribute to its short electrolyte infiltration diffusion path lengths and low charge transfer resistant.Graphical AbstractLSV curves measured at 5 mV/s in 1 M KOH solution for OER, the inset image is FE-SEM image of prepared Co3O4 materials. a Flower, b fiber, c sheet and d rod.n