High light-to-fuel efficiency and CO₂ reduction rates achieved on a unique nanocomposite of Co/Co doped Al₂O₃ nanosheets with UV-vis-IR irradiation

Abstract

A nanocomposite of Co/Co–Al2O3 nanosheets shows a high light-to-fuel efficiency and fuel production rate for photothermocatalytic CO2 reduction using CH4.

Formation of NiCo Alloy Nanoparticles on Co Doped Al2O3 Leads to High Fuel Production Rate, Large Light‐to‐Fuel Efficiency, and Excellent Durability for Photothermocatalytic CO2 Reduction

“…In addition, the reference samples of pure NiCo alloy nanoparticles with the Ni/Co molar ratios of 3.48 (labeled as Ni 3.48 Co), Ni nanoparticles supported on Co doped Al 2 O 3 nanosheets (labeled as Ni/Co–Al 2 O 3 ) were prepared. The reference samples of Ni nanoparticles supported on Al 2 O 3 nanosheets (labeled as Ni/Al 2 O 3 ) and Co nanoparticles supported on Al 2 O 3 nanosheets (labeled as Co/Al 2 O 3 ) were prepared according to the reported works [ 47,48 ] (see the Experimental Section in the Supporting Information).…”

“…[ 51 ] Metallic Co and Ni exist in Ni 1.60 Co/Co–Al 2 O 3 , consistent with the result of XRD and HRTEM. This is evidenced by weak peaks around 778.0 eV (Co), [ 48,51 ] and 851.8 eV (Ni). [ 47 ] Interestingly, as compared to the XPS peak around 852.6 eV of metallic Ni (e.g., in a reference sample of Ni/Al 2 O 3 , Supporting Information), [ 47,51 ] the peak of metallic Ni in Ni 1.60 Co/Co–Al 2 O 3 obviously shifts to 851.8 eV.…”

“…Recently, an approach of photothermocatalysis for CO 2 reduction by water, [ 33–35 ] hydrogen, [ 36–40 ] and methane [ 41–49 ] was developed. The approach is very efficient and promising as it well integrates low energy consumption of photocatalysis with high efficiency of thermocatalysis.…”

“…In the approach, photothermocatalytic CO 2 reduction by methane to produce carbon monoxide and hydrogen (CRM, CO 2 + CH 4 = 2CO + 2H 2 , Δ H 298 = 247 kJ mol −1 , usually referred to as dry reforming of methane) is very appealing and promising because it is able to achieve high r fuel and η at the same time. [ 44–48 ] Methane is utilized as reductant in photothermocatalytic CRM due to its abundance and low cost as major component of natural gas. Moreover, its products may be utilized as syngas to synthesize liquid fuels by industrial Fischer–Tropsch technology and acquire clean hydrogen fuel by industrial separation technology.…”

“…[ 41–49 ] Among the catalysts, nonprecious metal catalysts such as Ni and Co are appealing due to their earth abundance, low cost, and good catalytic activity. [ 43,45–48 ] However, unlike noble metal catalysts with good resistance to carbon deposition, nonprecious metal catalysts are prone to deactivation due to two side‐reactions of carbon deposition such as CO disproportionation (2CO = C + CO 2 , Δ H 298 = −171 kJ mol −1 ) and methane dissociation (CH 4 = C + 2H 2 , Δ H 298 = 75 kJ mol −1 ). The catalyst deactivation is major challenge for the practical application of photothermocatalytic CRM in greenhouse gas control and solar energy storage.…”