Atomically Dispersed Nickel Anchored on a Nitrogen‐Doped Carbon/TiO₂Composite for Efficient and Selective Photocatalytic CH₄Oxidation to Oxygenates

Abstract

Direct photocatalytic oxidation of methane to liquid oxygenated products is a sustainable strategy for methane valorization at room temperature. However, in this reaction, noble metals are generally needed to function as cocatalysts for obtaining adequate activity and selectivity. Here, we report atomically dispersed nickel anchored on a nitrogendoped carbon/TiO 2 composite (NiÀ NC/TiO 2 ) as a highly active and selective catalyst for photooxidation of CH 4 to C1 oxygenates with O 2 as the only oxidant. NiÀ NC/TiO 2 exhibits a yield of C1 oxygenates of 198 μmol for 4 h with a selectivity of 93 %, exceeding that of most reported high-performance photocatalysts. Experimental and theoretical investigations suggest that the single-atom NiÀ NC sites not only enhance the transfer of photogenerated electrons from TiO 2 to isolated Ni atoms but also dominantly facilitate the activation of O 2 to form the key intermediate * OOH radicals, which synergistically lead to a substantial enhancement in both activity and selectivity.

Synergy of Ag and AgBr in a Pressurized Flow Reactor for Selective Photocatalytic Oxidative Coupling of Methane

“…Methane oxidation by oxygen gas to C 1 oxygenates (e.g., CH 3 OH, CH 3 OOH, and HCHO) in the presence of water has been well-studied using oxide-based photocatalysts. The selectivity of products can be manipulated via the modification of different co-catalysts . For instance, a high primary products (CH 3 OOH and CH 3 OH) yield of 25.4 μmol/h and a selectivity of 95% were achieved over TiO 2 modified by Au-CoO x dual co-catalyst .…”

“…The selectivity of products can be manipulated via the modification of different co-catalysts. 9 For instance, a high primary products (CH 3 OOH and CH 3 OH) yield of 25.4 μmol/h and a selectivity of 95% were achieved over TiO 2 modified by Au-CoO x dual co-catalyst. 10 Up to now, photocatalytic methane conversion has already been achieved over TiO 2 , ZnO, WO 3 , etc.…”

Elevated photooxidation of CH4 to C1 liquid products over an anatase/rutile TiO2 biphase junction

“…4a, and displays strong quadruple signals of ·OH (●) that were detected under illumination, 21 accompanied by recognizable ·CH 3 signals (*). 22 If methanol was used as the ·OH trapping agent, as shown in Fig. 4b, an obvious sextet ·OOH signal (marked with triangles) and a detectable ternary signal corresponding to ·CH 2 OH were detected (marked with diamonds).…”

Amide Covalent Bonding Engineering in Heterojunction for Efficient Solar-Driven CO2 Reduction

“…16 Furthermore, the 13 C isotope labeling strategy (Figure 5c) provided additional evidence that the carbon of CO and CH 4 originated from CO 2 , rather than the self-decomposition of the catalyst. 4,12 In addition, the adsorption properties of CN-CQD for the reaction substrates were analyzed using water contact angle measurements (Figure S14) and CO 2 -temperature-programmed desorption (CO 2 -TPD, Figure 5d). The results revealed that CN-CQD exhibited a water contact Angle of approximately 17°, indicating good water wettability.…”