A TiO₂‐Co(terpyridine)₂ Photocatalyst for the Selective Oxidation of Cellulose to Formate Coupled to the Reduction of CO₂ to Syngas

Abstract

Immobilization of ap hosphonated cobalt bis(terpyridine) catalyst on TiO 2 nanoparticles generates ap hotocatalyst that allows coupling aqueous CO 2 -to-syngas (CO and H 2 )r eduction to selective oxidation of biomass-derived oxygenates or cellulose to formate.Anenzymatic saccharification pre-treatment process is employed that enables the use of insoluble cellulose as an electron-donating substrate under benign aqueous conditions suitable for photocatalytic CO 2 conversion. The hybrid photocatalyst consists of solely earthabundant components,and its heterogeneous nature allows for reuse and operation in aqueous solution for several days at 25 8 8C, reaching ac ellulose-to-formate conversion yield of 17 %. Thus,t he proof-of-concept for valorizing two waste streams (CO 2 and biomass) simultaneously into value-added chemicals through solar-driven catalysis is demonstrated.

Key role of light in highly efficient photothermocatalytic steam cellulose reforming on Co/CeO2–Al1Mg3O4.5

“…9,10 Biomass, including cellulose and lignin, has emerged as an ideal sacri-cial agent due to its abundance, low cost, and renewability. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] In the reaction process, the oxidation and decomposition of biomass are the rate-determining steps in the conversion of photocatalytic biomass to H 2, as it has a complex structure and high inertness. To promote the reaction, researchers commonly use highly alkaline conditions 3,18 (10 M NaOH and KOH), which is not conducive to practical application.…”

Nanocellulose‐Assisted Molecularly Engineering of Nitrogen Deficient Graphitic Carbon Nitride for Selective Biomass Photo‐Oxidation

“…Only a few studies have reported that lignocellulose is oxidized to HCOOH, owing to the positive valence band position of TiO 2 (3.0 eV vs RHE, PH = 7). [11] Graphitic carbon nitride (g-C 3 N 4 ) has a conduction band (CB) at −1.4 V and a valence band (VB) at 1.3 V that is suitable for most photocatalytic biorefineries. [12] However, pristine g-C 3 N 4 only affords unsatisfactory activity owing to limited visible-light absorption range, fast recombination of photo-excited charge carriers, and low specific surface area.…”

Solar-Driven Photothermal Catalytic Lignocellulosic Biomass-to-H2 Conversion

“…Recently, solar-driven photocatalytic H 2 production from lignocellulosic biomass provides a unique approach for the conversion of lignocellulosic biomass to H 2 , which has particularly attracted a lot of attention. − In this method, a semiconductor was used as the photocatalyst to accomplish both H 2 generation reaction and lignocelluloses decomposition reaction. − That is, the photogenerated electron can reduce protons to H 2 , while the hole can oxidize lignocellulosic biomass to H + , CO 2 , and organics. Because both photocatalyst and lignocellulosic biomass were solids, it is kinetically difficult to realize hole transfer between photocatalyst and lignocellulose owing to the absence of effective chemical collision.…”