Rationally designed nanoarray catalysts for boosted photothermal CO₂ hydrogenation

Abstract

A combined structural engineering strategy and thinning strategy were used to optimize nanoarray-based photothermal catalysts, showing a high CO2 conversion rate of 1780 mmol gCo-1 h-1.

Solar‐Driven CO2 Conversion via Optimized Photothermal Catalysis in a Lotus Pod Structure

“…This reaction rate corresponds to 1477 mmol g Co À 1 h À 1 based on Co mass and an estimated turnover frequency (TOF) of 2.39 s À 1 , approaching the highest reported mass activity of Co-based catalysts for photothermal CO 2 hydrogenation to CO (Table S2). [19] The measured activation energy is slightly lower but comparable to that of as-pyrolyzed CoÀ C (Figure S18), suggesting that H 2 activation mostly increase the active surface area of the catalyst rather than alter the nature of the catalytic site. In contrast, the Co + C catalyst (Figure S19) shows a low CO rate of 195 mmol g cat À 1 h À 1 even after H 2 activation (Figure 3b, black), demonstrating the importance of high Co dispersion and intimate Co/C interfaces for high catalytic activity.…”

“…[13][14][15][16]18,20,[28][29][30][31][32] When normalized to the mass of Co, the CO production rate is 2871 mmol g Co À 1 h À 1 with an estimated TOF of 4.65 s À 1 , superior to all other Co-based photothermal CO 2 hydrogenation catalysts reported to date (Table S2). [19,21,[33][34][35][36][37][38] K + À CoÀ C synthesized from KNO 3 and KCl show similar CO productivity and selectivity, demonstrating that the performance improvement is indeed caused by K + . Na + addition can also improve CO selectivity, but to a less extent than K + (Figure S25).…”

“…[8] Most of these catalysts are catalytically active nanoparticles dispersed on highsurface-area supports such as SiO 2 , [13][14][15] Al 2 O 3 , [15][16] TiO 2 , [17] CeO 2 [18] and Si. [19] They deliver 10 3 mmol g active À 1 h À 1 CO production rates based on the active material. This value drops to 10 1 mmol g cat À 1 h À 1 when normalized to the total catalyst mass (including the support) because of the low active material mass loading.…”

Two-dimensional nanomaterials: synthesis and applications in photothermal catalysis

“…Consequently, reducing the thickness of 2D nanomaterials is also an effective strategy to enhance photothermal activities. For example, He et al 109 synthesized SiNCs@Co with different substrate thicknesses, and explored the performance of photothermal CO 2 hydrogenation. Among the catalysts, 120 μm-SiNCs@Co exhibited superior performance for CO production (1780 mmol g Co −1 h −1 ), and the surface temperature of SiNCs@Co with a smaller thickness rapidly increased from room temperature to ∼360 °C.…”

Integrated Photothermal Nanoreactors for Efficient Hydrogenation of CO2

“…Recently, our previous work discovered that with the increase in cobalt loadings, cobalt-decorated silicon nanowires arrays (SNAs@Co) exhibited strong absorption in the near-infrared range [23]. Meanwhile, the further increase of cobalt loadings led to large particle size and low catalytic activity [24]. Therefore, it is highly desirable but challenging to develop new Jiahui Shen and Rui Tang have contributed equally to this work.…”