Dataset Information

Modulating oxygen coverage of Ti₃C₂T_x MXenes to boost catalytic activity for HCOOH dehydrogenation.

ABSTRACT: As a promising hydrogen carrier, formic acid (HCOOH) is renewable, safe and nontoxic. Although noble-metal-based catalysts have exhibited excellent activity in HCOOH dehydrogenation, developing non-noble-metal heterogeneous catalysts with high efficiency remains a great challenge. Here, we modulate oxygen coverage on the surface of Ti₃C₂T_x MXenes to boost the catalytic activity toward HCOOH dehydrogenation. Impressively, Ti₃C₂T_x MXenes after treating with air at 250?°C (Ti₃C₂T_x-250) significantly increase the amount of surface oxygen atoms without the change of crystalline structure, exhibiting a mass activity of 365?mmol·g^-1·h^-1 with 100% of selectivity for H₂ at 80?°C, which is 2.2 and 2.0 times that of commercial Pd/C and Pt/C, respectively. Further mechanistic studies demonstrate that HCOO* is the intermediate in HCOOH dehydrogenation over Ti₃C₂T_x MXenes with different coverages of surface oxygen atoms. Increasing the oxygen coverage on the surface of Ti₃C₂T_x MXenes not only promotes the conversion from HCOO* to CO₂* by lowering the energy barrier, but also weakens the adsorption energy of CO₂ and H₂, thus accelerating the dehydrogenation of HCOOH.

SUBMITTER: Hou T

PROVIDER: S-EPMC7447762 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Modulating oxygen coverage of Ti3C2Tx MXenes to boost catalytic activity for HCOOH dehydrogenation.

Hou Tingting T Luo Qiquan Q Li Qi Q Zu Hualu H Cui Peixin P Chen Siwei S Lin Yue Y Chen Jiajia J Zheng Xusheng X Zhu Wenkun W Liang Shuquan S Yang Jinlong J Wang Liangbing L

Nature communications 20200825 1

As a promising hydrogen carrier, formic acid (HCOOH) is renewable, safe and nontoxic. Although noble-metal-based catalysts have exhibited excellent activity in HCOOH dehydrogenation, developing non-noble-metal heterogeneous catalysts with high efficiency remains a great challenge. Here, we modulate oxygen coverage on the surface of Ti3C2Tx MXenes to boost the catalytic activity toward HCOOH dehydrogenation. Impressively, Ti3C2Tx M ...[more]

PMID: 32843636

Similar Datasets

Project description:Because of the high specific surface area, excellent electronic conductivity, facile Li diffusion, and rich functional groups, Ti2C-based MXenes have been widely used to improve the electrochemical property of lithium-sulfur batteries. The complex surface functionalization (such as -OH, -S, -F, and -O) of MXenes boosts the performance but also causes controversies about the favorable functionalized surface in the electrochemical reaction during the charge and discharge process. In the present work, a theoretical study based on density functional theory has been carried out to clarify the favorable functionalized surface by comparing pristine Ti2C and -OH-, -S-, -F-, and -O-functionalized Ti2C surfaces from the aspects of adsorption ability, electronic conductivity, and kinetic conversion ability. It is found that compared with severe polysulfide deformation on pristine Ti2C and Ti2C(OH)2 surfaces, Ti2CO2, Ti2CS2, and Ti2CF2 have effective polysulfide adsorption. Ti2CO2 has the largest surface adsorption energy, followed by Ti2CS2, and Ti2CF2 is the weakest. Meanwhile, the narrow-band gap semiconductor property of Ti2CO2 during adsorption indicates worse electronic conductivity than metallic Ti2CS2 and Ti2CF2. In addition, for the kinetic conversion ability, the Ti2CS2 surface has the fastest polysulfide conversion and Li diffusion, followed by Ti2CF2, and Ti2CO2 represents the slowest conversion and diffusion. Accordingly, because of the medium binding energy, good electronic conductivity, and fast polysulfide conversion and Li diffusion, Ti2CS2 is revealed to be the favorable functionalized surface. More importantly, the origin for the Ti2CS2 surface with medium adsorption ability represents the fastest polysulfide conversion, and Li diffusion is further clarified. The great affinity of the Ti2CS2 surface to the product Li2S leads to facile polysulfide conversion. The uniform charge distribution on the Ti2CS2 surface contributes to the fast Li diffusion.

Dataset Information

Modulating oxygen coverage of Ti₃C₂T_x MXenes to boost catalytic activity for HCOOH dehydrogenation.

Publications

Modulating oxygen coverage of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXenes to boost catalytic activity for HCOOH dehydrogenation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure