Altering Hydrogenation Pathways in Photocatalytic Nitrogen Fixation by Tuning Local Electronic Structure of Oxygen Vacancy with Dopant

Abstract

To avoid the energy‐consuming step of direct N≡N bond cleavage, photocatalytic N2 fixation undergoing the associative pathways has been developed for mild‐condition operation. However, it is a fundamental yet challenging task to gain comprehensive understanding on how the associative pathways (i.e., alternating vs. distal) are influenced and altered by the fine structure of catalysts, which eventually holds the key to significantly promote the practical implementation. Herein, we introduce Fe dopants into TiO2 nanofibers to stabilize oxygen vacancies and simultaneously tune their local electronic structure. The combination of in situ characterizations with first‐principles simulations reveals that the modulation of local electronic structure by Fe dopants turns the hydrogenation of N2 from associative alternating pathway to associative distal pathway. This work provides fresh hints for rationally controlling the reaction pathways toward efficient photocatalytic nitrogen fixation.

Regulating Local Electron Density of Iron Single Sites by Introducing Nitrogen Vacancies for Efficient Photo‐Fenton Process

“…In the meantime, with the increased amount of NVs in Fe 1 /CN, Fe 2p spectra shifts towards lower binding energy compared with Fe 1 /CN (Figure 4 d), manifesting that NVs are favorable to obtain reaction center Fe with higher local electron density. [22] The engineered NVs can redistribute the extra electrons to adjacent single Fe sites through the delocalized p-conjugated networks of pristine CN and result in higher local electron density, which is consistent with the XAFS results.…”

Photocatalysis and perovskite oxide-based materials: a remedy for a clean and sustainable future

“…In the associative pathway, the hydrogenation takes place with the sideway nitrogen, which is not directly attached to the surface of the photocatalyst, which generates the NH 3 . 323,324 The remaining nitrogen attached photocatalyst's surface undergoes hydrogenation and generates NH 3 . But this route is challenging because the chemisorption of nitrogen molecules on the surface of the catalyst is not easy; therefore, surface engineering is an important parameter to enhance the photocatalyst activity for nitrogen fixation.…”

Cu clusters/TiO2−x with abundant oxygen vacancies for enhanced electrocatalytic nitrate reduction to ammonia

“…[1][2][3][4] However, industrial NH 3 production still heavily relies on the energy-and capital-intensive Haber-Bosch process, which consumes $2% of global energy and causes a serious carbon emission. [5][6][7][8][9] Meanwhile, excessive nitrate distributed in the environment is a great threat to the human body, so the efficient treatment of it is necessary. [10][11][12][13] And the relatively low bond energy of NO 3 À (204 kJ mol À1 ) makes it a favorable alternative for the next conversion to other nitrogen-containing species compared with N 2 .…”