Ensemble-Exciting Effect in Pd/alk-Ti₃C₂ on the Activity for Efficient Hydrogen Production

Abstract

Creating active sites to improve the mass activity and durability of metal catalysts by elucidating the relationship between the metal and the support is a major challenge. In this study, ultrafine palladium nanoparticles (Pd NPs) were supported on alkalized Ti3C2 (alk-Ti3C2) to obtain a catalytically active interfacial ensemble. The catalyst Pd/alk-Ti3C2 with a Pd loading of 1.0 wt % exhibited the highest activity in ammonia borane (AB) hydrolysis reaction, with an initial turnover frequency of 230.6 min–1. A comprehensive analysis revealed that an ensemble-exciting effect originated from the Pd and the alk-Ti3C2. The hydroxylation of alk-Ti3C2 regulated the local coordination environment of Pd. Water and AB were effortlessly activated by the −OH group and Pd atom aggregates composed of electron-deficient support alk-Ti3C2 and electron-rich Pd, respectively. The efficient generation of hydrogen at the interface of Pd/alk-Ti3C2 was further guaranteed by the interfacial activation. This work on precision active sites opens new avenues for developing high-activity noble-metal catalysts for AB hydrolysis.

Metal–Support Synergistic Catalysis in Pt/MoO3–x Nanorods toward Ammonia Borane Hydrolysis with Efficient Hydrogen Generation

“…Hydrogen, as an important environmentally benign energy, has attracted widespread attention to meet the growing demand for social transportation and electronic devices. − However, efficient storage and safe delivery of H 2 remain a great challenge. , Hence, the development of chemical H 2 -storage materials has been regarded as a feasible and promising way for the future hydrogen economy. , Among the chemical H 2 -storage materials, ammonia borane (NH 3 BH 3 , AB) is a leading contender attracting tremendous research efforts, with the advantages of high hydrogen content (19.6 wt %), chemical nontoxicity, and superior stability in both aqueous solution and air at room temperature. − Although hydrolytic dehydrogenation of one AB molecule produces three H 2 molecules in the presence of suitable heterogeneous catalysts (normally noble metals, especially Pt and Rh), − developing a practically applicable catalyst, which is simultaneously capable of high reactivity and controlled hydrogen release, is the key to large-scale application of hydrogen energy . In addition, how to improve the cyclic stability of heterogeneous catalysts remains a challenge, owing to aggregation and the surface adsorption of poisonous B-containing byproducts.…”

“…1−4 However, efficient storage and safe delivery of H 2 remain a great challenge. 5,6 Hence, the development of chemical H 2 -storage materials has been regarded as a feasible and promising way for the future hydrogen economy. 7,8 Among the chemical H 2storage materials, ammonia borane (NH 3 BH 3 , AB) is a leading contender attracting tremendous research efforts, with the advantages of high hydrogen content (19.6 wt %), chemical nontoxicity, and superior stability in both aqueous solution and air at room temperature.…”

Element‐Doped Mxenes: Mechanism, Synthesis, and Applications

“…The application of flexible 2D MXene materials related to mechanical properties draws raising concern. [94][95][96] Chakraborty et al interpret the effect on mechanical properties about doping of semiconductor elements in MXene. [47] In the process of B substitution doping, it amplifies the strain and reduces the plane stiffness resulting in local deformation, producing a metallic system (Figure 4a).…”

“…The application of flexible 2D MXene materials related to mechanical properties draws raising concern. [ 94–96 ] Chakraborty et al. interpret the effect on mechanical properties about doping of semiconductor elements in MXene.…”

Highly effective palladium nanocatalyst supported in polymeric networks for the catalytic hydrogen generation from borane‐morpholine complex

“…In the light of this information, a schematic representation of the mechanism we proposed for the catalytic hydrolysis of MB was shown in Figure 6(b). [32][33][34][35] After determining that SPVI@Pd is an effective and efficient catalyst system for the hydrolysis reaction of MB, the effect of catalyst amount on the reaction rate was investigated. For this purpose, SPVI@Pd catalysts containing 1.5 (SPVI@Pd 1.5 ), 3.0 (SPVI@Pd 3.0 ), 4.5 (SPVI@Pd 4.5 ) and 6.0 mg (SPVI@Pd 6.0 ) Pd 0 were prepared by using masses of 50, 100, 150, 200 mg of dried SPVI hydrogel, respectively.…”