Alloying effect of Ni-Mo catalyst in hydrogenation of N-ethylcarbazole for hydrogen storage

Abstract

Liquid organic hydrogen storage with N-ethylcarbazole (NEC) as a carrier is a very promising method. The use of precious metal hydrogenation catalysts restricts the development in industrial grade. Efficient and low-cost hydrogen storage catalysts are essential for its application. In this work, a Ni-Mo alloy catalyst supported by commercial activated carbon was synthesized by impregnation method, and the Ni-Mo ratio and preparation conditions were optimized. The catalyst was characterized by XRD, XPS, H2-TPR, SEM, and TEM. The results showed that the doping of Mo could dramatically promote the catalytic hydrogenation of N-ethylcarbazole by the Ni-based catalyst. More than 5.75 wt% hydrogenation could be achieved in 4 h using the Ni-Mo catalyst, and the selectivity of the fully hydrogenated product 12H-NEC could be effectively improved. This result reduces the cost of hydrogenation catalysts by more than 90% and makes liquid organic hydrogen storage a scaled possibility.

Effects of molybdenum addition to activated carbon supported Ni‐based catalysts for CO2 methanation

“…They indicate the presence of Mo 3d in several regions located at 232.8, 229.4, and 228.3 eV. Based on the literature, the peaks at region Mo 6+ (232.8 eV), Mo 4+ (229.4 eV), and Mo 2+ (228.3 eV) are probably attributed to molybdenum oxidized phases, 72 resulting from the passivation step 73,74 . This meant that the Ni species had a strong metal‐support interaction between NiO and MoO 3 .…”

“…Over the sample of Ni/AC, it is found that the corresponding Ni2p spectra are shown in Fig. 8A, where 852.6, 854.8, and 856.3 corresponded to Ni 0 , Ni 2+ and Ni δ+ 73 . It was discovered that the catalytic activity of the catalysts at low temperatures of 250°C was significantly enhanced by reducing the binding energy of Ni 2p 3/2 .…”

“…The dissociative adsorption of CO 2 on the surface of the nickel atom produces adsorbed carbon (C ads ) for the 72 resulting from the passivation step. 73,74 This meant that the Ni species had a strong metal-support interaction between NiO and MoO 3 . It was likely that the presence of Mo caused a significant metal-support interaction between the support and the NiO species.…”

“…8A, where 852.6, 854.8, and 856.3 corresponded to Ni 0 , Ni 2+ and Ni δ+ . 73 It was discovered that the catalytic activity of the catalysts at low temperatures of 250°C was significantly enhanced by reducing the binding energy of Ni 2p 3/2 . Moreover, it is known that nickel atoms have 9.4 electrons in their 3d electron orbit and 0.6 electrons in their 4s electron orbit.…”

Comparative Studies on Full Dehydrogenation of Dodecahydro-N-Ethylcarbazole on Pd(111) and Ni(111) Surfaces: Mechanism and Catalytic Enhancement

“…Therefore, it is necessary to carry out detailed studies to improve the catalytic performance of Ni catalysts. , Introducing other metals to form alloy phases has been widely employed in the design of high-performance Ni-based alloy catalysts. In recent years, alloy catalysts such as Pd–Ni, , Ni–Mo, Ru–Ni, Ni–Pt, and La–Ni , have been reported, demonstrating improved catalytic reactivity. However, there is still a lack of theoretical work to explain the underlying mechanism of enhancement and to predict new candidates.…”