Engineering of crystal phase over porous MnO2 with 3D morphology for highly efficient elimination of H2S.

In this work, we have successfully triggered the aqueous auto-redox reactions between reductive Ce(OH)3 and oxidative MnO4 - /Pd2+ ions to form PdO/Mn3 O4 /CeO2 (PMC) nanocomposites. PMC could spontaneously self-assemble into compact encapsulation on the surface of halloysite nanotubes (HNTs) to form the final one dimensional HNTs supported PMCs (HPMC). It is identified that there exists strong synergistic effects among the components of PdO, Mn3 O4 , and CeO2 , and hence HPMC could show excellent performance on photoassisted thermal catalytic CH4 combustion that its light-off temperature was sharply reduced to be 180 °C under visible light irradiation. Based on detailed studies, it is found that the catalytic reaction process well follows the classic MVK mechanism, and adsorption/activation of O2 into active oxygen species (O*) should be the rate-determining step for CH4 conversion.

Highly ActivePdO/Mn3O4/CeO2 Nanocomposites Supported on One Dimensional Halloysite Nanotubes for Photoassisted Thermal Catalytic Methane Combustion.

Synthesis of hierarchical nickel sulfide nanotubes for highly efficient electrocatalytic urea oxidation

Effects of binary Co–Mn oxides promoters on low-temperature catalytic performance of Pd/Al2O3 for methane combustion

It is of practical importance to develop a stable and accessible methane combustion catalyst which could retain an excellent activity under drastic conditions. Herein, we introduce a facile approach to extend the stability of conventional Pd/Al2O3 catalysts through tailoring the pore size of mesoporous aluminas (MAs) and the interaction between Pd and Al. By modulating the addition of templates (deoxycholic acid and polyvinylpyrrolidone), a series of MAs with tunable and uniform pore size were obtained through a designed sol-gel method. Unexpectedly, Pd/MA-800-5 catalyst prepared with relatively large pore size (ca. 12 nm) MAs exhibited an efficient and sustained performance under a variety of operating conditions, while those prepared with small pore size (ca. 5-7 nm) MAs suffered from a significant loss of activity during high temperature cyclic reactions (280-850 °C) due to the decomposition of confined PdO. The enhancement could be attributed to the suitable particle size, higher crystallinity, generated active sites, improved reducibility, and thermal stability of PdO species. Moreover, the variation of pore size also resulted in a different reaction mechanism. Such a pore size promotion strategy effectively invoked a superior catalytic performance while keeping the catalyst components simple, which can be extended to prepare other high-performance metal oxide-supported catalysts for catalytic applications.

Facile Strategy to Extend Stability of Simple Component-Alumina-Supported Palladium Catalysts for Efficient Methane Combustion

The development of highly efficient and cheap electrocatalysts for the oxygen evolution reaction (OER) is highly desirable in typical water-splitting electrolyzers to achieve renewable energy production, yet it still remains a huge challenge. Herein, we have presented a simple procedure to construct a new nanofibrous hybrid structure with the interface connecting the surface of CeO2 and CoO as a high-performance electrocatalyst toward the OER through an electrospinning-calcination-reduction process. The resultant CeO2-CoO nanofibers exhibit excellent electrocatalytic properties with a small overpotential of 296 mV at 10 mA cm-2 for the OER, which is superior to many previously reported nonprecious metal-based and commercial RuO2 catalysts. Furthermore, the prepared CeO2-CoO nanofibers display remarkable long-term stability, which can be maintained for 130 h with nearly no attenuation of OER activity in an alkaline electrolyte. A combined experimental and theoretical investigation reveals that the excellent OER properties of CeO2-CoO nanofibers are due to the unique interfacial architecture between CeO2 and CoO, where abundant oxygen vacancies can be generated due to the incomplete matching of atomic positions of two parts, leading to the formation of many low-coordinated Co sites with high OER catalytic activity. This research provides a practical and promising opportunity for the application of heterostructured nonprecious metal oxide catalysts for high-efficiency electrochemical water oxidation.

Interface Engineering of Heterogeneous CeO2-CoO Nanofibers with Rich Oxygen Vacancies for Enhanced Electrocatalytic Oxygen Evolution Performance.

Topological materials with robust topological surface states can be a class of very promising catalysts in electrocatalysis. In this study, a freestanding 2D topological insulator (TI) nanomaterial, namely, TaIrTe4 monolayer with low Ir-loading, which can be exfoliated from the bulk phase with the layered structure, is demonstrated to be dynamically, mechanically, and thermodynamically stable under the first-principles calculations. More intriguingly, coupled with good conductivity, a 2D TaIrTe4 monolayer can be considered as an alternative to noble metal Pt-based electrocatalyst for the oxygen reduction reaction (ORR). Our calculations revealed that on the surface of the TaIrTe4 monolayer, the adsorbed O2 molecules can be effectively activated and dissociated into two separated O* species through a very small energy barrier (0.28 eV, even lower than that of Pt(111)). When the four-electron (4e) dissociation path of ORR occurs on the TaIrTe4 monolayer, a very small overpotential of 0.47 V can be observed, which can be even comparable to the Pt(111) surface. In addition, the 2D TaIrTe4 monolayer can also exhibit high selectivity, effectively inhibiting the formation of byproduct H2O2. It can be revealed that the TI topological states can have an important effect on the excellent ORR catalytic activity of the 2D TaIrTe4 monolayer. Undoubtedly, the design of ORR electrocatalysts based on the fascinating topological materials can be a new and effective way to replace the precious metal Pt-based ORR electrocatalysts. 

TaIrTe4 Monolayer with Topological Insulator Characteristic: A New and Highly Efficient Electrocatalyst toward Oxygen Reduction Reaction

In view of the weak aromatic characteristic resulting from the weak π-bonding ability (different from the analogous graphene), employing two-dimensional (2D) silicene and germanene monolayers could be one of the most promising ways to realize a new type of highly efficient and nonprecious catalyst for the hydrogen evolution reaction (HER). However, the HER activity of pristine silicene and germanene has to be improved, although both of them can exhibit a good change trend. Particularly, the hydrogen phenomenon can occur under moderate or high H* coverage on 2D silicene and germanene. To overcome these bottlenecks, in this study we identify the most effective strategy through doping P with a lone pair to significantly improve the HER catalytic activity under a high H* coverage, by screening a series of IIIA (i.e., B, Al, Ga, In and Tl) and VA (i.e., N, P, As, Sb and Bi) heteroatoms with different electronegativity under detailed DFT calculations. It is revealed that the doped P atoms and almost all the Si/Ge atoms can uniformly serve as highly active sites. Especially, in view of the existence of the lone pair, doping P effectively prevents hydrogenation (even under full H* coverage) by increasing the structural rigidity. Moreover, the P-doping concentration also plays a crucial role in obtaining high HER activity. The relevant mechanisms have been analyzed in detail. Clearly, all these fascinating findings are beneficial for realizing new HER electrocatalysts based on the excellent silicene or germanene nanomaterials, and even other Si/Ge-related materials in the near future.

Doping P atom with a lone pair: an effective strategy to realize high HER catalytic activity and avoid deactivation under wide H* coverage on 2D silicene and germanene by increasing the structural rigidity.

Lusi Zhao

Papers

Facile Strategy to Extend Stability of Simple Component-Alumina-Supported Palladium Catalysts for Efficient Methane Combustion

Interface Engineering of Heterogeneous CeO2-CoO Nanofibers with Rich Oxygen Vacancies for Enhanced Electrocatalytic Oxygen Evolution Performance.

TaIrTe4 Monolayer with Topological Insulator Characteristic: A New and Highly Efficient Electrocatalyst toward Oxygen Reduction Reaction

Doping P atom with a lone pair: an effective strategy to realize high HER catalytic activity and avoid deactivation under wide H* coverage on 2D silicene and germanene by increasing the structural rigidity.

2D RhTe Monolayer: A highly efficient electrocatalyst for oxygen reduction reaction.