Ruthenium–Cobalt Nanoalloy Embedded within Hollow Carbon Spheres as a Bifunctionally Robust Catalyst for Hydrogen Generation from Water Splitting and Ammonia Borane Hydrolysis

Abstract

Developing high-efficiency and low-cost catalysts for the hydrogen evolution reaction (HER) and hydrogen generation from chemical hydrogen storage materials are both significant and critical for the exploitation and utilization of hydrogen energy. Herein, we reported a ruthenium−cobalt alloy (Ru, 1.8 wt %) enriched in hollow carbon spheres (denoted RuCo@HCSs) synthesized through a wet vacuum impregnation method followed by pyrolysis treatment. RuCo alloys are obtained by direct reduction of Ru and Co chloride precursors, avoiding hydrothermal and washing processes, and the Ru/Co ratio of the alloy can be precisely controlled. The RuCo@HCS catalyst not only displays outstanding HER performance with a low overpotential (η 10 ) and Tafel slope (21 mV and 32 mV dec −1 in 1.0 M KOH, 57 mV and 48 mV dec −1 in 0.5 M H 2 SO 4 , and 49 mV and 59 mV dec −1 in 1.0 M phosphate-buffered saline) within a wide pH range but also offers a high turnover frequency (TOF) value of 784 mol H2 min −1 mol cat −1 for the hydrolysis of ammonia borane under ambient conditions. The excellent catalytic performance of RuCo@HCSs is attributed to the special hollow embedded configuration and collaborative effect between carbon shells and RuCo alloys. Density functional theory calculations reveal that the excellent catalytic performance of RuCo@HCSs originates from the carbon shells activated by the electron transferred from the embedded metal nanoparticles. This work provides a convenient route for preparing highly active and inexpensive metal/carbon composite bifunctional catalysts.

Phosphorus-Doped 3D RuCo Nanowire Arrays on Nickel Foam with Enhanced Electrocatalytic Activity for Overall Water Splitting

“…The C 1s spectrum of RuCoP/NF can be divided into four peaks that can be assigned to OH–C=O (290.1 eV), C=O (288.7 eV), C–O/sp 2 –C (286.2 eV), and C–C/C=C (284.9 eV). 36 The additional peaks of RuCoP/NF at 283.7 and 280.7 eV were attributed to Ru 3d 3/2 and 3d 5/2 , respectively. On account of the overlapping of the Ru 3d peak with the C 1s peak, the Ru 3p spectrum was mainly used to explore the electronic property.…”

Facile soft-chemistry synthesis of Co-Ru nanoalloys: influence of the composition on the catalytic activity for the acceptorless dehydrogenation of alcohols.

“…4 For Fischer-Tropsch catalysis, [5][6][7] it has been known for a long time that very small amounts of Ru, used as a promotor, help to increase the reducibility of Co species. 5,8 Recently, there has been an increasing interest in Co-Ru bimetallic catalysts for various reactions such as the hydrogenation of furfural to furfuryl alcohol, 9 the decomposition of the Li 2 CO 3 discharge product in Li-CO 2 batteries, 10 the hydrolysis of aminoborane, [11][12][13] the conversion of CO 2 to methane 14 or the oxygen [15][16][17] and hydrogen 12,13,[16][17][18][19][20] evolution reactions. Bimetallic compounds are often generated through high temperature pyrolysis under neutral atmospheres and the active phase is stabilized thanks to interactions with a carbonaceous support such as carbon quantum dots, carbon nanotubes or graphene.…”

Hydrolysis of B2pin2 over Pd/C Catalyst: High Efficiency, Mechanism, and in situ Tandem Reaction

“…Over the past two decades, it has become an significant mainstream in the world to explore clean and renewable energy, due to the ever‐increasing of the depletion of nonrenewable fossil resources (including natural gas, oil and coal) and the crazy development of global economy [1–4] . Among all kinds of renewable energy resources, hydrogen is regarded as one of the most potential alternative source with high chemical energy (142 MJ/kg) due to its clean, abundant, efficient and sustainable characteristics [5–7] .…”