Amorphous Alloy Architectures in Pore Walls: Mesoporous Amorphous NiCoB Alloy Spheres with Controlled Compositions via a Chemical Reduction

Abstract

Amorphous bimetallic borides are an emerging class of catalytic nanomaterial that has demonstrated excellent catalytic performance due to its glass-like structure, abundant unsaturated active sites, and synergistic electronic effects. However, the creation of mesoporous Earth-abundant bimetallic metal borides with tunable metal proportion remains a challenge. Herein, we develop a sophisticated and controllable dual-reducing agent strategy to synthesize the mesoporous nickel−cobalt boron (NiCoB) amorphous alloy spheres (AASs) with adjustable compositions by using a soft template-directed assembly approach. The selective use of tetrabutylphosphonium bromide (Bu 4 PBr) is beneficial to generate well-defined mesopores because it both moderates the reduction rate by decreasing the reducibility of M 2+ species and prevents the generation of soap bubbles. Our meso-Ni 10.0 Co 74.5 B 15.5 AASs generate the highest catalytic performance for the hydrolytic dehydrogenation of ammonia borane (AB). Its high performance is attributed to the combination of optimal synergistic effects between Ni, Co, and B as well as the high surface area and the good mass transport efficiency due to the open mesopores. This work describes a systematic approach for the design and synthesis of mesoporous bimetallic borides as efficient catalysts.

Mesoporous Zeolitic Imidazolate Frameworks

“…These evidences illustrate that the mesopores within mZIF-8 are periodic (or ordered). [44][45] The particle size of mZIF-8 is small, so there is no higher ordered diffraction peak of the mesopores in its SAXS profile. [46][47] As shown in Figure 1g, the N 2 adsorption/desorption isotherms of mZIF-8 present a hysteresis loop, indicating the presence of the mesopores.…”

Soft Template‐Based Synthesis of Mesoporous Phosphorus‐ and Boron‐Codoped NiFe‐Based Alloys for Efficient Oxygen Evolution Reaction

“…The use of Bu 4 PBr not only prevented the formation of soap bubbles (arising from the H 2 produced by the decomposition of DMAB in the micellar system) by increasing the surface tension of the solution but also helped limit the reduction rate by decreasing the reducibility of the metal species. [ 11 ] After the dissolution of the Bu 4 PBr powder, the metal precursor solution was added to the previously prepared block copolymer solution. The resulting solution mixture was transferred to a two‐necked flask (100 mL) and kept at 40 °C in an oil bath and purged with Ar for 3.0 min to remove the oxygen present to prevent metal oxidation during the reaction.…”

“…[8] In particular, conductive metallic mesoporous materials contain highly exposed active sites and exhibit efficient mass/electron transport in a range of electrochemical reactions. [9][10][11] In addition, metallic mesoporous materials with larger mesopores facilitate the smooth and rapid Controlling the morphology, composition, and crystalline phase of mesoporous nonnoble metal catalysts is essential for improving their performance. Herein, well-defined P-and B-codoped NiFe alloy mesoporous nanospheres (NiFeB-P MNs) with an adjustable Ni/Fe ratio and large mesopores (11 nm) are synthesized via soft-template-based chemical reduction and a subsequent phosphine-vapor-based phosphidation process.…”

“…[ 8 ] In particular, conductive metallic mesoporous materials contain highly exposed active sites and exhibit efficient mass/electron transport in a range of electrochemical reactions. [ 9–11 ] In addition, metallic mesoporous materials with larger mesopores facilitate the smooth and rapid mass transport of large molecules. [ 12 ] Mesoporous structures can be formed in metals using templates based on lyotropic liquid crystals (LLCs) [ 13 ] or by the hard‐template approach.…”

Multidimensional Nonstoichiometric Electrode Materials for Electrochemical Energy Conversion and Storage

“…[99] Kang et al developed a sophisticated and controllable dual-reducing agent strategy to synthesize the mesoporous NiCoB amorphous alloy with adjustable compositions. [100] Zhang's group reported the solvothermal synthesis of RuNi alloy nanostructures with multilayered nanosheets through the co-reduction of ruthenium(III) chloride hydrate and nickel(II) acetylacetonate with formaldehyde reductant agent and polyvinylpyrrolidone surfactant. [101] Dealloying refers to the selective dissolution of one or more constituent elements from alloys, which is efficient to construct nanoporous structures from bulk alloys.…”