Niko Heikkinen

Dr. Niko Heikkinen

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2018 in Journal of CO2 Utilization
Verified
Journal Article
Closed access
FVFrancisco Vidal Vázquez
Francisco Vidal Vázquez
JKJoonas Koponen
Joonas Koponen
VRVesa Ruuskanen
Vesa Ruuskanen
CBCyril Bajamundi
Cyril Bajamundi
AKAntti Kosonen
Antti Kosonen
PPPaolo Piermartini
Paolo Piermartini

20 August 2024 in ACS Nano
Verified
Journal Article
Open access
KSKaline N. da Silva
Kaline N. da Silva
SSShwetha Shetty
Shwetha Shetty
SSSam Sullivan−Allsop
Sam Sullivan−Allsop
RCRongsheng Cai
Rongsheng Cai
SWShiqi Wang
Shiqi Wang
Pedro CamargoPedro Camargo
Pedro Camargo
Plasmonic catalysis has been employed to enhance molecular transformations under visible light excitation, leveraging the localized surface plasmon resonance (LSPR) in plasmonic nanoparticles. While plasmonic catalysis has been employed for accelerating reaction rates, achieving control over the reaction selectivity has remained a challenge. In addition, the incorporation of catalytic components into traditional plasmonic-catalytic antenna-reactor nanoparticles often leads to a decrease in optical absorption. To address these issues, this study focuses on the synthesis of bimetallic core@shell Au@AuPd nanoparticles (NPs) with ultralow loadings of palladium (Pd) into gold (Au) NPs. The goal is to achieve NPs with an Au core and a dilute alloyed shell containing both Au and Pd, with a low Pd content of around 10 atom %. By employing the (photo)electrocatalytic nitrite reduction reaction (NO2RR) as a model transformation, experimental and theoretical analyses show that this design enables enhanced catalytic activity and selectivity under visible light illumination. We found that the optimized Pd distribution in the alloyed shell allowed for stronger interaction with key adsorbed species, leading to improved catalytic activity and selectivity, both under no illumination and under visible light excitation conditions. The findings provide valuable insights for the rational design of antenna-reactor plasmonic-catalytic NPs with controlled activities and selectivity under visible light irradiation, addressing critical challenges to enable sustainable molecular transformations.

26 August 2019 in Catalysts
Verified
Journal Article
Open access
PDF file
MMMarco Marchese
Marco Marchese
NHNiko Heikkinen
Niko Heikkinen
EGEmanuele Giglio
Emanuele Giglio
Andrea LanziniAndrea Lanzini
Andrea Lanzini
JLJuha Lehtonen
Juha Lehtonen
Matti ReinikainenMatti Reinikainen
Matti Reinikainen
A Co-Pt/γ-Al2O3 catalyst was manufactured and tested for Fischer–Tropsch applications. Catalyst kinetic experiments were performed using a tubular fixed-bed reactor system. The operative conditions were varied between 478 and 503 K, 15 and 30 bar, H2/CO molar ratio 1.06 and 2.11 at a carbon monoxide conversion level of about 10%. Several kinetic models were derived, and a carbide mechanism model was chosen, taking into account an increasing value of termination energy for α-olefins with increasing carbon numbers. In order to assess catalyst suitability for the determination of reaction kinetics and comparability to similar Fischer–Tropsch Synthesis (FTS) applications, the catalyst was characterized with gas sorption analysis, temperature-programmed reduction (TPR), and X-ray diffraction (XRD) techniques. The kinetic model developed is capable of describing the intrinsic behavior of the catalyst correctly. It accounts for the main deviations from the typical Anderson-Schulz-Flory distribution for Fischer–Tropsch products, with calculated activation energies and adsorption enthalpies in line with values available from the literature. The model suitably predicts the formation rates of methane and ethylene, as well as of the other α-olefins. Furthermore, it properly estimates high molecular weight n-paraffin formation up to carbon number C80.

14 February 2024 in Physical Chemistry Chemical Physics
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Journal Article
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NHNiko Heikkinen
Niko Heikkinen
JLJuha Lehtonen
Juha Lehtonen
RPRiikka L. Puurunen
Riikka L. Puurunen
This work presents a modeling approach for atomic layer deposition (ALD) to describe the effect of particle geometry on the reactant diffusion and reaction in a tortuous and porous particle.

11 August 2022 in Physical Chemistry Chemical Physics
Verified
Journal Article
Open access
PDF file
NHNiko Heikkinen
Niko Heikkinen
JLJuha Lehtonen
Juha Lehtonen
LKLaura Keskiväli
Laura Keskiväli
JYJihong Yim
Jihong Yim
SSShwetha Shetty
Shwetha Shetty
MPMatti Putkonen
Matti Putkonen
Atomic layer deposition (ALD) was used to deposit a protective overcoating (Al2O3) on an industrially relevant Co-based Fischer–Tropsch catalyst.

6 August 2024 in ChemCatChem
Verified
Journal Article
Open access
NHNiko Heikkinen
Niko Heikkinen
DDDorela Dhamo
Dorela Dhamo
IUIda Uotila
Ida Uotila
Matti ReinikainenMatti Reinikainen
Matti Reinikainen
RDRoland Dittmeyer
Roland Dittmeyer
In this study we focus on the iron‐based catalyst to produce C2−C4 olefin hydrocarbons via the high‐temperature Fischer‐Tropsch synthesis. Promoters have a significant impact on catalyst stability, activity, and product selectivity. Therefore, we investigated the effect of the Cu promoter in an Fe−Cu−K/SiO2 catalyst. We compared the catalyst without Cu and 1, 2, 3, 4, and 5 wt % Cu loadings. The overall catalyst activity increased from 0 to 3 wt % Cu loading and started to decrease at 4 and 5 wt % Cu loadings. Although overall catalyst activity had an optimum with 3 and 4 wt % Cu loading, the Cu loading had a negligible effect on product selectivity. However, when compared to a non‐Cu promoted catalyst, the Cu addition increased the selectivity towards olefinic C2−C4 hydrocarbons. The Fischer‐Tropsch experiments were performed in a tubular reactor system at 300 °C, 21 bar and H2 : CO=2 at different feed volume flows, with hydrogen activation. According to the performed temperature‐programmed dynamic chemisorption analysis, the Cu promoter assisted the iron reduction, and the lower overall activity to 0–2 wt % Cu loading might relate to insufficient dissociated H surface species, rather than the availability of C from dissociated CO.