Morphology‐Engineered Highly Active and Stable Ru/TiO₂ Catalysts for Selective CO Methanation

Abstract

Ru/TiO 2 catalysts exhibit an exceptionally high activity in the selective methanation of CO in CO 2 -and H 2 -rich reformates,b ut suffer from continuous deactivation during reaction. This limitation can be overcome through the fabrication of highly active and non-deactivating Ru/TiO 2 catalysts by engineering the morphology of the TiO 2 support. Using anatase TiO 2 nanocrystals with mainly {001}, {100}, or {101} facets exposed, we show that after an initial activation period Ru/TiO 2 -{100} and Ru/TiO 2 -{101} are very stable,w hile Ru/ TiO 2 -{001} deactivates continuously.E mploying different operando/in situ spectroscopies and ex situ characterizations, we show that differences in the catalytic stability are related to differences in the metal-support interactions (MSIs). The stronger MSIs on the defect-richT iO 2 -{100} and TiO 2 -{101} supports stabilize flat Ru nanoparticles,w hile on TiO 2 -{001} hemispherical particles develop.The former MSIs also lead to electronic modifications of Ru surface atoms,r eflected by the stronger bonding of adsorbed CO on those catalysts than on Ru/TiO 2 -{001}.

Controlling CO2 Hydrogenation Selectivity by Metal‐Supported Electron Transfer

“…It is quite surprising and interesting that on 1Ru/a-TiO 2 catalyst CO cannot be hydrogenated into CH 4 as Ru/TiO 2 is usually regarded as one of the best candidates for selective methanation of CO. [31] Thea dsorption and subsequent dissociation of CO on catalyst is usually regarded as acritical step in CO hydrogenation to methanation. [32] However, am icrocalorimetry measurement of the CO adsorption suggested that the adsorption strengths on the two samples are similar ( % 145 kJ mol À1 ), Figure S12.…”

Photocatalytic Cleavage of β-O-4 Ether Bonds in Lignin over Ni/TiO2

“…Semiconductor, such as TiO 2 , attracted the attention of many researchers due to its versatile advantages involving stable catalytic performance and low cost [28][29][30]. It has been widely reported that the introduction of transition metal [31][32][33] or noble metal nanoparticles [34][35][36] to TiO 2 support is beneficial for electron transfer in the photochemical reaction process. For instance, Farnood et al demonstrated a novel Bi and Pt co-modified TiO 2 catalyst for the photo-oxidation of lignin under solar light for the generation of guaiacol, vanillic acid, vanillin and 4-phenyl-1-buten-4-ol [37].…”

Surfactant-assisted hydrothermal synthesis of MoS2 micro-pompon structure with enhanced photocatalytic performance under visible light

“…It is widely accepted that the photodegradation efficiency of the catalyst is greatly affected by its bandgap, morphology, crystallinity, defects, and size [3,17,18]. Morphology engineering is a crucial factor in the synthesis of an efficient and stable catalyst [19]. Up to now, different morphologies of MoS 2 such as nanosheets, nanospheres, and nanoflowers are successfully synthesized by the hydrothermal route [20][21][22].…”