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Glucose–Carbon Hybrids as Pt Catalyst Supports for the Continuous Furfural Hydroconversion in Gas Phase
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Green Chemistry and Environmental Processes

LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avenida de Fuente Nueva, 18071 Granada, Spain
Author to whom correspondence should be addressed.
Catalysts 2021, 11(5), 643;
Received: 2 April 2021 / Revised: 7 April 2021 / Accepted: 9 April 2021 / Published: 19 May 2021
(This article belongs to the Special Issue Green Chemistry and Environmental Processes)
This Special Issue was designed based on two complementary principles, both aimed at developing environmentally friendly production processes, in which catalysis plays a leading role. Green chemistry is the utilization of a set of principles that reduce or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products [1], while under the environmental processes heading, we want to bring together the technologies currently applied and the new proposals for the treatment of pollutants and the protection of the environment. The quest for such products and processes is transversal to all areas of study and continues to be a challenge to scientists. The aim of this Special Issue was to provide readers with examples of such processes already operating, proving that it is possible to make research “green”. This Special Issue contains four articles.
One of them, by Morales-Torres et al., deals with glucose–carbon hybrids as Pt catalyst supports for continuous furfural hydroconversion in gas phase [2]. Several carbon materials were tested as dopants of glucose hydrothermal treatment, namely carbon nanotubes, reduced graphene oxides, carbon black and activated carbon, and Pt was supported on these carbon hybrids. Catalysts were used for the gas phase furfural hydroconversion in mild conditions (1 atm and below 200 °C), saving energy and avoiding the use of organic solvents. Pt catalysts supported on these “greener” supports and processes showed better catalytic performance at low temperatures than the catalyst prepared on reference material. No catalyst deactivation was found after several hours on stream, showing the “green” potential of these samples.
Park et al. reported on the pyrolysis of polyethylene terephthalate (PET) over carbon-supported Pd catalysts [3]. This process usually leads to harmful polycyclic hydrocarbons and biphenyl derivatives. For 5 wt.% Pd on activated carbon (Pd catalyst/PET ratio of 0.05), the formation and generation of noxious materials could be avoided from 400 to 700 °C. The concentration of the 2-naphthalenecarboxylic acid produced was reduced by 44%, while the concentration of biphenyl-4-carboxylic acid was reduced by 79% compared to non-catalytic pyrolysis at 800 °C. Amine compounds were also generated in smaller amounts. This Pd catalyst proved to be a promising material for a more environmentally friendly, “green” and reliable method to eliminate industrial plastic waste.
The paper by Yu et al. dealt with Zr(SO4)2/silica and Zr(SO4)2/activated carbon catalysts for the esterification of malic acid to dimethyl malate using methanol [4]. When this process is performed with traditional homogenous catalysts, no recycling is possible and undesirable side reactions occur. In the reported work, a 99% selectivity of dimethyl malate was obtained on the two catalysts, which was much higher than that of conventional H2SO4 (75%) and unsupported Zr(SO4)2∙4H2O (80%) catalysts, with a similar conversion. Moreover, the catalysts could be easily separated from the reaction media by filtration with almost no loss of activity.
Husnain et al. reported on low-temperature selective catalytic reduction (SCR) of NH3 using maghemite (γ-Fe2O3) catalysts [5]. The nanoparticles prepared by a facile method exhibited better NH3-SCR activity and selectivity than the catalyst prepared by a co-precipitation procedure, but also showed improved SO2 tolerance. The best materials showed a larger surface area, better pore structure, high concentration of lattice oxygen and surface-adsorbed oxygen, good reducibility, a large number of acid sites, lower activation energy, adsorption of reactants and unstable nitrates on the surface.
As guest editors of this Special Issue, we are thankful to all the authors who contributed and also to the staff members of MDPI for their editorial support. We trust readers will find the papers of this Special Issue to be helpful and interesting examples of the use of “Green Chemistry and Environmental Processes”.


Portuguese FCT—Fundação para a Ciência e a Tecnologia, I.P., under the Scientific Employment Stimulus—Institutional Call (CEECINST/00102/2018) and Associate Laboratory for Green Chemistry—LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020) and the Spanish Project ref. RTI 2018-099224-B100 funded by ERDF/Ministry of Science, Innovation and Universities. S.M.-T. also acknowledges the Ramón y Cajal contract (RYC-2019-026634-I/AEI/10.13039/501100011033) from MINECO.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice; Oxford University Press: Oxford, UK, 1998; ISBN 0198502346. [Google Scholar]
  2. Morales-Torres, S.; Pastrana-Martínez, L.M.; Pérez-García, J.A.; Maldonado-Hódar, F.J. Glucose–Carbon Hybrids as Pt Catalyst Supports for the Continuous Furfural Hydroconversion in Gas Phase. Catalysts 2021, 11, 49. [Google Scholar] [CrossRef]
  3. Park, C.; Kim, S.; Kwon, Y.; Jeong, C.; Cho, Y.; Lee, C.G.; Jung, S.; Choi, K.Y.; Lee, J. Pyrolysis of Polyethylene Terephthalate over Carbon-Supported Pd Catalyst. Catalysts 2020, 10, 496. [Google Scholar] [CrossRef]
  4. Yu, P.; Chen, C.; Li, G.; Wang, Z.; Li, X. Active, Selective, and Recyclable Zr(SO4)2/SiO2 and Zr(SO4)2/Activated Carbon Solid Acid Catalysts for Esterification of Malic Acid to Dimethyl Malate. Catalysts 2020, 10, 384. [Google Scholar] [CrossRef][Green Version]
  5. Husnain, N.; Wang, E.; Fareed, S.; Anwar, M.T. Comparison on the Low-Temperature NH3-SCR Performance of γ-Fe2O3 Catalysts Prepared by Two Different Methods. Catalysts 2019, 9, 1018. [Google Scholar] [CrossRef][Green Version]
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MDPI and ACS Style

Carabineiro, S.A.C.; Morales-Torres, S.; Maldonado-Hódar, F.J. Green Chemistry and Environmental Processes. Catalysts 2021, 11, 643.

AMA Style

Carabineiro SAC, Morales-Torres S, Maldonado-Hódar FJ. Green Chemistry and Environmental Processes. Catalysts. 2021; 11(5):643.

Chicago/Turabian Style

Carabineiro, Sónia A. C., Sergio Morales-Torres, and Francisco J. Maldonado-Hódar. 2021. "Green Chemistry and Environmental Processes" Catalysts 11, no. 5: 643.

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