Perovskite Oxide Catalysts for Enhanced CO₂ Reduction: Embroidering Surface Decoration with Ni and Cu Nanoparticles

Round 1

Reviewer 1 Report

The work submitted by Osti et al. is a really interesting and valuable study of perovskite oxide catalysts surface decoration with Ni and Cu nanoparticles for improving the CO2 reduction. The prepared catalysts were characterized using fruitful combination of different techniques such as XRD, N2 physisorption, H2-TPR, SEM-EDX, CO2-TPD and XPS. It should be mentioned that the manuscript is well-written, the introduction clearly lays out reasons for studying of such system. But I have some major questions concerning the data presented and would recommend the presented manuscript for publication in the Catalysts journal only after the following issues are taken into account in a revised version.

Comments to authors:

1)     In table 1 authors provide the Bulk (EDX) and surface (XPS) composition of the prepared samples, I have a question concerning the quantitative XPS analysis – from fig 7 I could not see the signal from Ni2p which is overlapped with La3d region. How the authors did the quantitative analysis of Ni content – please provide the peak fitting.

2)     Cu2p spectra should be included in the manuscript

3)     Figure 6 – From my opinion it would be useful to zoom in the region of Cu and Ni.

4)     What is the particles size distribution for Cu, Ni and CuNi catalysts?

5)     There is the article (https://doi.org/10.1016/j.cattod.2016.04.022) published by Prof. Rupprechter devoted to the surface composition changes of CuNi during methane decomposition. Synchrotron-based operando NAP-XPS indicated segregation of Ni on the nanoparticle surface when reactivity set in for CuNi-ZrO2 – at the temperature above 500-600K. Did the authors tooks this into account? What happened with the samples after catalytic test?

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, La0.9FeO3 perovskite support was prepared and then loaded by citric-acid templated wet impregnation with Ni, Cu and Ni-Cu to prepare three different catalysts. Ni and Cu reached 50% of CO2 conversion at 500°C while Ni-Cu co-loaded LFO achieved the same conversion at lower temperature. It can be accepted after addressing the following concerns：

1. How did Ni-Cu co-loading enhance the photocatalytic activity? Please explain this.

2. The optical properties of catalysts should be measured by UV-vis absorption spectra.

3. The photocatalytic performance of this work should be compared with other similar systems.

4. Some recent reports about perovskite-based photocatalysts for CO2 conversion should be cited, such as Inorg. Chem. 2023, 62, 1752−1761; Sol. RRL 2023, 7, 2300038.

Minor editing of English language required.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Currently the article could be published in its present form, without any additional action from authors.