Catalytic transfer hydrogenation of levulinate ester intoγ-valerolactone over ternary Cu/ZnO/Al2O3 catalyst

An effective catalytic transfer hydrogenation (CTH) process of bio-based levulinate esters into γ-valerolactone (GVL) was explored over ternary Cu/ZnO/Al2O3 catalyst which was prepared by coprecipitation method and could be sustainably used. As a result, quantitative conversion of ethyl levulinate (EL) and 99.0% yield of GVL were obtained in the CTH process using i-PrOH as hydrogen donor. The Cu/ZnO/Al2O3 catalyst with high-surface-area could be reused at least four times without the loss of catalytic activity. Furthermore, the structure and properties of Cu/ZnO/Al2O3 catalyst was characterized through XRD, BET, SEM, TEM and H2-TPR. Also, the influence of different support oxides and calcination temperatures was investigated.

Catalytic conversion of ethyl lactate to 1,2-propanediol over CuO

An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol(1,2-PDO) over CuO was investigated.Among the catalysts we tested, CuO, Cu2 O and Co showed excellent catalytic activity for the conversion of ethyl lactate to 1,2-PDO in water, and CuO was more active and gave the best result. The 1,2-PDO yield of 93.6% was achieved when Zn acted as a reductant. The results indicated that in situ formed hydrogen by the oxidation of Zn in water is more effective than gaseous hydrogen, which failed to produce the 1,2-PDO from ethyl lactate.From a practical point of view, the present method may provide a useful route for the production of 1,2-PDO from ethyl lactate.

Improved two-step hydrothermal process for acetic acid production from carbohydrate biomass

An improved two-step process for converting carbohydrate biomass to acetic acid under hydrothermal conditions is proposed. The first step consists of the production of lactic acid from carbohydrate biomass, and the second step consists of conversion of the lactic acid obtained in the first step to acetic acid using CuO as an oxidant. The results indicated that CuO as an oxidant in the second step can significantly improve the production of high-purity acetic acid from lactic acid, and the maximum yield of acetic acid was 61%, with a purity of 90%. The yield of acetic acid obtained using the improved two-step hydrothermal process from carbohydrate biomass, such as glucose, cellulose and starch, was greater than that obtained using traditional two-step process with H2O2 orO2. In addition, a proposed pathway for the production of acetic acid from lactic acid in the second step with CuO was also discussed. The present study provides a useful two-step process for the production of acetic acid from carbohydrate biomass.

Heterogeneous Cu_2O-mediated ethylene glycol production from dimethyl oxalate

An efficient process for the conversion of dimethyl oxalateinto ethylene glycol with high selectivity and high yield over Cu_2O was investigated. In situ formed Cu as a true catalytically active species showed a good catalytic performance for DMO conversion to produce EG in 95% yield.

A review of anodic catalysts and their application in(non-)Kolbe electrocatalytic decarboxylation of carboxylic acids

Biomass,as the exclusive and abundant organic resources,is considered to be the promising renewable resource.Carboxylic acids are one of the many compounds that can be obtained from raw biomass.Decarboxylation of carboxylic acids into fuels and chemicals via electrochemical method at mild reaction condition has been studied for many years.The(non-)Kolbe reaction,one of the oldest organic electrochemical reactions,is the decarboxylation of carboxylic acids to produce alkanes,alcohols,esters,etc.And electrode materials influence the production of electrocatalytic decarboxylation products from carboxylic acids.Therefore,this work mainly reviews the recent advances in applications of anodic materials for(non-)Kolbe electrocatalytic decarboxylation of carboxylic acids.It discusses the reaction mechanism of(non-)Kolbe electrolytic reaction,and the electrocatalytic oxidation of carboxylic acid using different electrodes and electrolytic systems to synthesize fuels and chemicals.Also,various types of electrode catalysts,such as Pt-based catalysts,C-based catalysts,and other catalysts,are introduced in detail.Finally,the challenges and future trends of the(non-)Kolbe reaction of carboxylic acids are presented.This review found that platinum-based electrocatalysts proved to be the most promising catalysts at present.And in recent years,a variety of synthesis methods have been developed to synthesize small size and high-performance noble metal based amorphous catalysts.Another approach is to study catalysts without platinum electricity,such as Ru,Ir,Ti and carbon materials.The review is helpful in understanding and know the anodic materials and their application in(non-)Kolbe electrocatalytic decarboxylation of carboxylic acids for the readers.

Carbon materials in electrocatalytic oxidation systems for the treatment of organic pollutants in wastewater:A review

Carbon materials are widely used as catalysts in electrocatalytic oxidative(EO)degradation of wastewater due to their large specific surface area and low cost.Carbon materials can also be used as catalyst carriers for EO reactions due to their ease of functionalization with other heteroatoms and metals/metal oxides.To improve the catalytic activity and current efficiency of carbon materials,modifying the structural and physicochemical properties of conventional carbon materials are common improvement method.This review briefly outlines the recent research progress of carbon materials in EO for organic pollutants degradation.It also discusses the modification strategies and corresponding electrocatalytic properties of various carbon materials(carbon nanomaterials and porous carbon materials),and explores the EO mechanism.Finally,some summaries of the remaining challenges and future developments of carbon materials in the field of electrocatalysis are given.

Catalytic hydrotreatment of alkaline lignin and its consequent influences on fast pyrolysis

The current state of lignin has been characterized by these three:(1)as one of the main components in lignocellulosic biomass with an abundant amount;(2)not be taken seriously but treated as a waste product;(3)underutilized due to a complex and stubborn structure.However,lignin can be a rich source for hydrocarbons and aromatic compounds when gives appropriate utilization.In this work,we have studied the hydrotreatment of alkaline lignin(AL)under relatively mild conditions and further investigated the characterization of hydrogenated lignin(HL),especially the behavior during fast pyrolysis.The recovery of the HL decreased with increasing reaction temperature from 60 wt.%to 41 wt.%in the range of 150-250℃.The hydrotreated products were analyzed using Elemental Analysis,FTIR(for HL)and GC-MS(for bio-oil).The HL samples were found to have a higher hydrogen/carbon atomic effective ratio(H/C_(eff) ratio)and a higher degree of saturation than AL.Compared to the internal structure of the lignin before and after hydrotreatment,the side chain groups were removed from AL during the process.After that,from the fast pyrolysis of HL,it was observed that more light hydrocarbons and aromatic compounds were formed than that of AL.Furthermore,fast pyrolysis in the hydrogen atmosphere revealed that more volatile fractions were released compared to the Helium atmosphere.The total olefins yield was increased for HL compared AL from 1.02 wt.%to 3.1 wt.%at 250℃for 7 hours.This study of HL is instructive to some extent for the industrial utilization of lignin.