1. Let's convert only 3rd page of Excel file to PDF and then merge this PDF file with itself using C#.

static void Main(string[] args)
{
    // Merge two PDF files.
    // 1. Let's get a PDF from .xlsx.
    // 2. Let's merge this PDF with itself.
    ExcelToPdf x = new ExcelToPdf();
    x.PageStyle.PageSize.Letter();
    x.PageStyle.PageMarginTop.mm(5);

    // Set PDF as output format.
    x.OutputFormat = SautinSoft.ExcelToPdf.eOutputFormat.Pdf;

    // Let's convert only 3rd page.
    x.Sheets.Custom(new int[]{3});

    string excelFile = Path.GetFullPath(@"d:\test.xlsx");
    FileInfo pdfFile = new FileInfo(Path.ChangeExtension(excelFile, ".pdf"));
    string singlePdf = Path.Combine(pdfFile.Directory.FullName, "Single.pdf");


    try
    {
        // 1. Convert Excel to PDF.
        x.ConvertFile(excelFile, pdfFile.FullName);

        // 2. Merge the PDF file with itself.
        x.MergePDFFileArrayToPDFFile(new string[] { pdfFile.FullName, pdfFile.FullName },
            singlePdf);

        System.Diagnostics.Process.Start(singlePdf);
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
        Console.ReadLine();
    }

}

2. Let's convert Excel file to PDF and next split the PDF document by pages using C#:

static void Main(string[] args)
{
    // Split PDF by pages.
    // 1. Let's get a PDF with 3 pages from .xlsx.
    // 2. Let's split it by 3 PDF files and show them.
    ExcelToPdf x = new ExcelToPdf();
    x.PageStyle.PageSize.Letter();
    x.PageStyle.PageMarginTop.mm(5);

    // Set PDF as output format.
    x.OutputFormat = SautinSoft.ExcelToPdf.eOutputFormat.Pdf;

    string excelFile = Path.GetFullPath(@"d:\test.xlsx");
    FileInfo pdfFile = new FileInfo(Path.ChangeExtension(excelFile, ".pdf"));

    try
    {
        // 1. Let's get a PDF with 3 pages from .xlsx.
        x.ConvertFile(excelFile, pdfFile.FullName);

        // 2. Let's split it by 3 PDF files and show them.
        // Create a directory for storing separate PDFs.
        DirectoryInfo pdfDir = pdfFile.Directory.CreateSubdirectory("My Pages");
        x.SplitPDFFileToPDFFolder(pdfFile.FullName, pdfDir.FullName);

        // Show result
        FileInfo[] pageFiles = pdfDir.GetFiles("*.pdf");
        Console.WriteLine("Resulting PDF files:\n");
        foreach (FileInfo pageFile in pageFiles)
        {
            Console.WriteLine(pageFile.Name);
        }

    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }

    Console.ReadLine();
}

«Excel to PDF .Net» can be used on 32 and 64-bits platforms with .NET Framework 4.0, .NET Core 2.0 and higher. The component doesn't require Microsoft Excel or any other software. It's absolutely standalone and independent library.

Our product is compatible with all .NET languages and supports all Operating Systems where .NET Framework and .NET Core can be used. Note that «Excel to PDF .Net» is entirely written in managed C#.