CO-tolerant RuNi/TiO2 catalyst for the storage and purification of crude hydrogen

Abstract

Hydrogen storage by means of catalytic hydrogenation of suitable organic substrates helps to elevate the volumetric density of hydrogen energy. In this regard, utilizing cheaper industrial crude hydrogen to fulfill the goal of hydrogen storage would show economic attraction. However, because CO impurities in crude hydrogen can easily deactivate metal active sites even in trace amounts such a process has not yet been realized. Here, we develop a robust RuNi/TiO2 catalyst that enables the efficient hydrogenation of toluene to methyl-cyclohexane under simulated crude hydrogen feeds with 1000–5000 ppm CO impurity at around 180 °C under atmospheric pressure. We show that the co-localization of Ru and Ni species during reduction facilitated the formation of tightly coupled metallic Ru-Ni clusters. During the catalytic hydrogenation process, due to the distinct bonding properties, Ru and Ni served as the active sites for CO methanation and toluene hydrogenation respectively. Our work provides fresh insight into the effective utilization and purification of crude hydrogen for the future hydrogen economy.

Enhanced Low-Temperature CO2 Methanation over Bimetallic Ni–Ru Catalysts

“…The CO adsorption on Ru/CeO 2 yielded a dominating IR band at 2066 cm –1 and a wide signal at 1980 cm –1 , which were ascribed to the multicarbonyl adsorbed on oxidized Ru sites as [Ru n + –(CO) x ] and the linearly bound CO on the Ru site at the Ru–CeO 2 interface, respectively. For the monometallic Ni catalyst, no CO adsorption bands remained after desorption, indicating that the interaction between Ni and CO is poor . Interestingly, a significant red shift of the CO adsorption band on the Ru site occurred from 0.2Ru (2066 cm –1 ) to 20Ni0.2Ru samples (2053 cm –1 ), indicating the higher electronegativity of Ru species in 20Ni0.2Ru samples as a result of electron transfer from Ni to Ru, which agrees well with the XPS data.…”

“…For the monometallic Ni catalyst, no CO adsorption bands remained after desorption, indicating that the interaction between Ni and CO is poor. 38 Interestingly, a significant red shift of the CO adsorption band on the Ru site occurred from 0.2Ru (2066 cm −1 ) to 20Ni0.2Ru samples (2053 cm −1 ), indicating the higher electronegativity of Ru species in 20Ni0.2Ru samples as a result of electron transfer from Ni to Ru, which agrees well with the XPS data.…”

“…The CO-TPD results (Figure S5) showed CO desorption at a high-temperature region (450−800 °C) over both 20Ni and 20Ni0.2Ru samples, which is likely due to dissociative adsorption of CO on Ni. An additional signal of CO desorption at a low-temperature range (60−250 °C) observed over 20Ni0.2Ru can be attributed to the desorption of CO on Ru species, 38 suggesting the presence of Ru can enhance the CO adsorption.…”

Structure-performance correlation on bimetallic catalysts for selective CO2 hydrogenation

“…Compared with the monometallic catalysts, significant interactions between Ni and Ru can be observed in all bimetallic samples, where the Ru reduction peaks shift to higher temperatures while the Ni ones all shift to lower temperatures in H 2 -TPR. 37,39,40 Among them, the strongest Ni and Ru interaction is observed on Ru@Ni/TiO 2 . However, rather than a continuous peak as in the case of Ni–Ru solid solution formation, there is a shoulder peak centred at around 373 °C for Ni@Ru/TiO 2 , which can be attributed to the reduction of interfacial RuO x –TiO 2 .…”

Atomic Insights into the Cu Species Supported on Zeolite for Direct Oxidation of Methane to Methanol via Low‐Damage HAADF‐STEM

“…Our additional case studies show this low-damage HAADF-STEM imaging technique is not restricted to the low-loading Cu/ZSM-5 catalysts (Figure S37, S38 and Notes S8, Supporting Information) but applicable for the exploration of intrinsic structures of more beam-sensitive catalytic materials (Figure S39, S40 and Notes S9, Supporting Information). [34]…”